First birthday parties are my absolute favorite, mostly because it’s so much fun to watch a little babe figure out how to eat cake for the first time! My tiniest niece turned one a few weeks ago, and I was so delighted to get to make her smash cake. It got me thinking about sharing my best tips on smash cakes with all of you, since they’re super easy to make and the perfect DIY project if you’re planning a first birthday for your little one (or in charge of the cake for someone else’s babe). From the perfect sized cake pans to a great vanilla cake recipe and decorating ideas, I’ve got you covered!
The Perfect Smash Cake Size
Since babies are small (and their stomach’s are even smaller), you’re going to need a set of tiny cake pans to bake your layers. I absolutely love these 4-inch cake pans because they’re the perfect size, have removable bottoms for easy release, and they come in a set of four so you can bake multiple layers at once.

I typically bake three layers for smash cakes, but have also created a four-layer tower cake that ended up being super cute for a first birthday. It’s totally up to you on how many layers to bake, but a 4-inch diameter is just the right amount of cake in my opinion.
Vanilla Smash Cake Recipe
You don’t have to get crazy with a recipe for your smash cake. In fact, vanilla cake with vanilla buttercream is the perfect starter cake for a baby. It’s simple, classic, and pretty universally loved. I’ve got a great, easy vanilla cake + vanilla buttercream recipe modified for those 4-inch cake pans below. Here’s what it looks like on the inside:

Since it’s an adapted version of my vanilla cake recipe, it’s totally tasty! As in, you’re probably gonna want to finish off whatever your little one doesn’t.

Vanilla Smash Cake Recipe
Ingredients
- 1 1/4 Cups (130g) cake flour, sifted before measuring
- 1 tsp baking powder
- 1/4 tsp baking soda
- 1/2 tsp salt
- 1/3 Cup (77g) unsalted butter, room temperature
- 3/4 Cup (155g) granulated white sugar
- 1 egg + 1 egg yolk, room temperature
- 1/4 Cup (60g) sour cream, room temperature
- 1 1/2 tsp vanilla extract
- 1/2 Cup (118ml) whole milk, room temperature
Instructions
- Preheat the oven to 350°F. Prepare three 4-inch cake pans by spraying the sides and bottom with cooking spray (Baker’s Joy is my favorite). Sift the cake flour and then measure by spooning and leveling it in your measuring cup. Add the cake flour, baking powder, baking soda, and salt into a bowl and whisk to combine. Set aside.
- In the bowl of your stand mixer (a handheld mixer works fine too!), cream the butter for on high for two minutes until it’s light and fluffy. Add in sugar and continue to mix on high for another two minutes, scraping down the bowl and paddle as needed. Turn the mixer to low, add the egg and yolk and mix thoroughly. Scrape down the bowl and paddle and add the vanilla and sour cream. Mix for one minute on high, scraping down the bowl and paddle once more.
- With the mixer on low speed, add in the dry ingredients and mix until just combined. Add the milk slowly and mix until just incorporated. Scrape down the sides and bottom of the bowl and give it a few stirs to make sure there are no lumps (without over-mixing). The batter will be slightly thick, but pourable.
- Pour batter into prepared cake pans (about 2/3 of the way full) and bake for 25 minutes. They’re done when they spring back to the touch and a toothpick inserted into the middle comes out clean. Let the cakes cool in the pan for five minutes before turning them out onto a wire rack for an additional few hours of cooling. Make sure they’re entirely room temperature before filling and frosting with vanilla buttercream frosting.
Notes
Smash Cake Decorating Ideas
The best thing about smash cakes is they’re going to get totally destroyed. That means you don’t have to get too intricate with your cake decorating or fret about design flaws. While you can decorate the cake any way you want, here are a few of my favorite ideas (with tutorial links to help you get the look!):
Smash Cake With Pretty Piping
This is one of my favorite easy looks for smash cakes, and the same design I created for my little niece! All you need is a few of your favorite piping tips and a smooth frosted cake.

After frosting the cake with buttercream, I chilled it for thirty minutes while I mixed up a buttercream color palette (there are five different colors on this beauty). Then, I piped rosettes with Wilton Tip 1M, ruffles with Wilton Tip 104, and filled the rest in with Wilton Tip 4B to create open stars.
Spatula Painted Smash Cake
If you’re wanting something colorful, yet super simple, this spatula painted technique is perfect! All you need is a color palette with three or more colors and a small icing spatula.

To get the look, fill and frost the cake and chill it in the refrigerator for thirty minutes while you mix up your buttercream color palette. Then, apply the colored buttercream to the cake by swiping it on with your icing spatula in a random pattern. There’s a full tutorial with additional tips here. You could also use the same technique to create longer spatula swipes for a look like this:

Smash Cake With Ganache Drip
This was a smash cake I created for an elegant first birthday party and I love the look so much! It’s a simple semi-naked cake design topped with white chocolate ganache drips.

If you want to top a cake like this with fresh flowers, be sure to check out this blog post first. You’ll want to be sure to choose flowers that are either edible or food-safe (non-poisonous) and prepare them properly before placing them on the cake. When your little one is ready to smash it up, remove the flowers and let them go crazy!
However you decide to decorate, this vanilla smash cake recipe is sure to be baby approved. Let me know if you end up trying it in the comments below, or tag me on Instagram so I can see what you whipped up!
Hi Whitney! This is so beautiful, I just love vibrancy of the colors. You do such great work, it is always a joy to see what you come up with next. Take care 🙂
Thanks so much, Stacey!! I’m a big fan of your cakes (and gorgeous blog!) too!! <3
How can I substitute cake flour with plain flour
Hi Remya! You can substitute all purpose flour, but the cake will be more dense and heavy. The pride of this cake recipe is that it’s light and fluffy! Luckily, you can make DIY cake flour using all purpose flour and it’s super easy to do – that way you can ensure that the end result is the perfect texture.
To make your own cake flour, spoon and level one cup of all-purpose flour and remove 2 Tbsp. Add 2 Tbsp of cornstarch. Repeat per the amount of cake flour you need, then sift the flour and cornstarch mixture 4 times (don’t skip that step!). After sifting, spoon and level to re-measure the amount of cake flour you need.
My littlest ones cake smash photo shoot is this weekend and I might just make ALL of these and surround her with beautiful sugar creations! lol Thanks for the inspo!
That would be amazing, Christine! Happy birthday to your little one and hope she loves her cake!
Hi
These are so beautiful
Thank you for posting your tutorials
The cake smash I am attempting fir my daughter’s first birthday is themed orange pink and teal. Do you think these colours would work together in the longer spatular swipes?
I was thinking teal on the bottom then orange then pink.
Hi Becky-Lee! I think orange, pink, and teal will look wonderful with a spatula painted design! I say go for it!
I’m really surprised that there is only one egg and one egg yolk.
Do you think I can add sprinkles to make it a funfetti cake? Thanks!!
Hi Terri! It’s a really small cake (only three 4-inch layers), so 1 egg and 1 yolk work perfectly. Any more eggs would start to weigh down the cake. And you can totally add sprinkles to this recipe! I would add about 1/3 cup of sprinkles (coated in a little flour so they don’t sink!) to the batter at the end.
I’m so glad you only use this amount of eggs, I’ve used three eggs in a 6inch smash cake once and it tasted too eggy! Can’t wait to try this!
Hi Whitney, I want to make one of these cakes for the first birthday photoshoot. What size cake stands are you using?
Yay, Jessica! I use a 6 inch cake stand for 4 inch cakes.
Hi Whitney, if I want to bake this cake in 2 5-inch cake, how long should I bake them for? Thank you!!!
Hi there! I’ve never used a 5-inch cake pan before but from what I know about this recipe I think they should be fully baked in 28-30 min. Let me know how it goes!
Hi again, I ended up baking 2 5in cake pans for 32 mins. It came out perfect and tasted REALLY good !! Made a smash cake with your vanilla buttercream recipe. It turned out perfect.
Yay!! I’m so happy it worked out in the 5 inch tins!! So glad you loved the recipe for the cake and the buttercream 🙂 thanks for letting me know!
Batter came out delicious! Only thing was, when I took my cake out of the oven, it had a big dip in the middle, making the cake not fully even across the top. Is this normal?
Hi Miranda! If the cake dipped in the middle in the baking process, it could mean a few different things went wrong: 1) check to see that your baking powder is fresh. It expires every 6 months, and if it’s expired it will cause the cake to dip in the center because it won’t have enough leavening agent. 2) make sure your ingredients are room temp. If they are colder than room temp, it will mess with the chemistry of the cake and could cause dipping. 3) Make sure you only mix for the exact amount of time specified in the recipe. Overmixing leads to the cake dipping in the center. 4) Check your oven temperature internally. Sometimes the display will read one temp while the oven is actually a different temp.
Most of the time the culprit is either overmixing the batter or expired baking powder. I hope it’s an easy fix for you because this recipe should be failproof! And if you need to cut the tops of these cakes to level them out, they should be salvageable even with a dipped center.
Sadly, I ensured all of these things were correct and all of my cakes still dipped. I had even tripled the recipe to make 3X the cakes, as I needed a variety – now I have a LOT of time, energy, ingredients wasted and the worst part…. no cake for my babies first birthday 🙁 I could cry!
Oh no, Cynthia! I’m so sorry to hear that! I just made this recipe for my niece’s birthday last week and it came out totally fine.. were you able to salvage the cake layers even though they had sunken in the middle? Usually if you torte the cake layer you can cut off the uneven tops and salvage them.
Hi! Do you think I could use buttermilk instead of whole milk in this recipe? Would I use the same amount? Thanks!
Hi Liz! You can certainly substitute buttermilk for the whole milk in this recipe. Just make sure it’s room temperature before adding it at the end and use the same amount.
These are all so beautiful! I cant wait for my daughters 1st birthday <3 Would it be okay to add funfetti to the vanilla cake, would it alter the bake time or anything? I havent baked in years!!
So fun, Emily! You can totally add rainbow sprinkles to this cake, just make sure they’re not the type that will dye your batter. The best kind are ones that are coated in caranuba wax (like these https://amzn.to/2yfiEzi). Toss about 1/4 Cup of rainbow sprinkles in 2 tsp flour, then fold them into the batter at the end and use the same baking time 🙂
Hello!
I dont have sour cream. What substitute I shall use? Thanks in advance!
The best substitute is full fat greek yogurt, but you can also omit the sour cream and use buttermilk in place of the whole milk to add extra moisture (that’s what sour cream does in a cake recipe).
Hey Whitney,
Today is the day with full of happiness as I baked the fluffy spongy Vanilla cake finally!! It came out very well. Thanks so much Whitney! My next goal is to achieve chocolate cake 🙂
I’m so happy to hear that, Benazir!! Thanks for letting me know!
Hi Whitney
What can I use in place of dairy or soy? My baby is allergic to both. She can have almond or oat milk. Would it work, or is there a better alternative? Also, I would love to use minimal amount of sugar or none at all. Can I use Apple sauce or pineapple or orange juice? Anything other than granulated sugar? Stevia? Thanks so much.
Hi Natalie! I wish I had some suggestions for you on how to alter this cake recipe to be dairy-free and reduced sugar, but I have never attempted either of those things so I can’t say for sure how it will all affect the chemistry of this recipe. I am planning on testing vegan vanilla cakes in the coming weeks but until I can nail down a great recipe, I would recommend finding a smash cake recipe that is dairy-free and reduced sugar to begin with. That way you know it’s been tested and approved!
Hi there. So i made the cake and used homemade applesauce instead of sour cream and 1/4 cup of sugar and 1/4 cup of almond milk. It didn’t rise at all. Any idea why? It’s my first time baking so I don’t even know where to start 🙁
Hi Natalie! There is a lot of chemistry involved in baking and when you alter a recipe with substitutions, there’s always a risk it won’t come out as intended by the recipe writer. Since you reduced both the sugar and the liquid amounts, the ratio of wet to dry ingredients is thrown off significantly. The only way I can guarantee success with this recipe is to make it as it is written, or make substitutions without reducing the liquid/dry ingredient amounts.
Thank you! This makes sense. I will try to do it as directed but dairy free! Thanks again!
Hi, would you know how long I’d need to increase the baking time for if I used two 4″ cake pans rather than 3?
Thanks
Hi Felicity! The baking time will be the same 🙂
Hi Whitney! Just tested this ahead of my little girl’s birthday next week and it is delish!
If I wanted to use bigger tins, can I just double the recipe?
Hi Anisha! So happy you love this recipe as much as I do! This recipe is the same as my vanilla cake recipe, so if you want to bake this in larger tins I would use this version: https://sugarandsparrow.com/vanilla-cake-recipe/
Planning on making two of these, one for my son’s first bday on the 11th and one for his smash cake photos this weekend. Do you use kosher sea salt or a different kind? Can I double the vanilla buttercream recipe so I can store the extra in the fridge for the following week?
Trying to plan out how I want to make the 2 cakes, tips are appreciated, thank you!
Hi Christy! I just use regular Kosher Salt (not Kosher Sea Salt), but I think any salt of your choice will be just fine. This is the brand I use: https://amzn.to/3dLaVrk. Yes, you can certainly double the vanilla buttercream recipe and store half in the fridge for the following cake. When you’re ready to use it, just bring it back to room temp and re-whip it with your stand mixer on low for about 30 seconds to bring it back to frosting consistency. Excited for you to make these and celebrate your son’s first birthday! So fun!!
Hi Whitney!
I’m about to start making this cake, but I only have 1 cup of unsalted butter (and still need to make the buttercream icing!)
Can I use salted butter and omit the .5 tsp of salt?
Thank you so much!!!
Hi Meagan! I believe it will work to use the salted butter and omit the added salt in this recipe, but I’ve never tried it before so I can’t say for sure. Let me know how it goes if you end up trying it with salted butter!
How much buttercream frosting do I need for this cake? Thanks
Hi Jan! One batch of this vanilla buttercream recipe will be enough for filling, frosting, and decorating a cake of this size: https://sugarandsparrow.com/vanilla-buttercream-recipe/
I used this recipe and substituted the sugar for Truvia Sweet Complete (I was going for a smash cake that wouldn’t be high in sugar and too sweet but would be enjoyed by all of us and this was a winner! I will definitely be using this recipe again in the future. I made a sugar free swiss buttercream to go with it.
Yay, Jennifer! So happy to hear that this recipe was a hit and that subbing in Truvia worked!
I plan on making this recipe for my daughter’s first birthday coming up. After making and decorating the cake, does it need to be stored in the fridge until serving or can it sit out at room temperature? Thank you!
Hi Jansen! It’s up to you – it doesn’t require refrigeration but I always like to refrigerate my cakes until a few hours before serving just to keep all the details intact. Happy birthday to your little one!
Would I beable to use this same mixture for cupcakes?
Hi Kat! You can. This recipe would make a small batch of cupcakes, maybe 10-12. If you need more cupcakes than that, you can use this vanilla cupcake recipe (same recipe, just scaled up to make more): https://sugarandsparrow.com/vanilla-cupcake-recipe/
Thank you so much!
Hi! I’m planning to make this for my daughter’s first birthday next month. It’s just beautiful! Can you tell me how you made the colors? How much food coloring for each one? This may be a silly question but I’m a major amateur.
Thanks!
Hi Tina! I never measure out the amount of food coloring I use but the colors I used on this cake were AmeriColor Fuchsia, Navy, and Teal. After frosting the cake with white buttercream I divided the remaining buttercream into four different bowls and colored two of the bowls Fuchsia (one pastel and one vibrant), one bowl a light Navy, and one bowl Teal. I have a post on how to color buttercream here that should help with eyeballing those colors: https://sugarandsparrow.com/how-to-color-frosting/
Hi Whitney,
What is the height of the four inch baking pans that you used? I just tried this recipe with the cakes in the oven now. I also used 4in baking pans but only had enough batter for 2 and a 1/2 cakes.
Hi Amanda! My 4 inch pans are 2 inches tall. Are yours taller than that? I usually have enough for four layers!