How to Convert My Layer Cake Recipes into Sheet Cakes

how to bake a sheet cake from layer cake recipe

In the midst of this crazy pandemic, I have seen so many of you turn to baking to pass the time and escape a little. It’s a really beautiful thing and I’m so inspired by it. I’ve got tons of cake recipes for you to try while you’re homebound, and while I tend to write them for layer cakes, I wanted to show you how to easily convert them into sheet cakes! This way, if you don’t have round cake pans or want to keep things simple with a single layer cake, you can use any of my cake recipes to do it! 

sheet cake recipes by sugar and sparrow

Sheet cakes are very nostalgic for me because they’re what I was raised on. Every year for my childhood birthdays, my mom would bake a single layer cake in a casserole dish, add canned frosting with a butter knife, and top it all with simple birthday candles. It was glorious! 

yellow cake recipe with chocolate frosting sheet cake

The sheet cake in this photo looks really similar, but it’s all homemade. I baked my Yellow Cake Recipe in a 9 x 13 casserole dish and frosted it with my Favorite Chocolate Buttercream. You don’t need a ton of cake tools or fancy techniques to make a sheet cake (I frosted this one with a spoon to get those swoops) but if you want to get creative with a non-traditional design, go crazy!

how to frost a sheet cake

Making the Right Amount of Batter

To bake my layer cake recipes in a 9 x 13 dish or pan, you’ll want to fill it only halfway full. My cake recipes have a bit of rise to them, and filling the pan more full will result in either 1) a really tall single layer of cake or 2) an overflow disaster. Since I know ingredients are semi-scarce right now, I don’t want you to make a big batch of cake batter when you aren’t going to use it all. So here’s a list of my layer cake recipes that you can convert following the instructions below:

For the cakes listed below, you’ll need to half the recipe to make the right amount of batter: 

The cakes listed below can be made as-is, but fill the 9 x 13 pan no more than half full. OR, if you really want to do the math, you can ⅓ the cake portion of the recipe to make just the right amount: 

Preparing the Sheet Cake Pan 

Once you’ve found the perfect recipe, you’ll need to prepare the pan you’re using for best results. You can use a 9 x 13 inch glass or ceramic casserole dish, or a metal pan of the same dimensions. I tend to use glass or ceramic dishes (especially love this one that came as part of a set from Crate & Barrel) just because I love the way they look right out of the oven, but you can use whatever you have on hand.

Either way, prepare the pan or dish by spraying the sides and bottom generously with cooking spray (I love Baker’s Joy for this). You can alternatively grease the pan generously with vegetable oil, or just grease the sides and place a piece of parchment paper on the bottom.

Baking the Sheet Cake 

Once you’ve filled your prepared pan or dish with cake batter (remember, no more than ½ full!) bake it at the oven temperature the recipe instructs. For my cake recipes, I always bake at 350ºF. Add 5 minutes to the baking time in the original recipe and check for doneness then by inserting a toothpick into the center of the cake. It’s done when the toothpick comes out clean.

how to bake a sheet cake in 9 x 13 pan

If it seems to need more time, add an additional 3-5 minutes to the baking time and check again. 

Frosting and Decorating the Sheet Cake 

You can use any of my frosting recipes to decorate your sheet cake, and if the cake recipe you chose calls for a specific buttercream recipe, be sure to half that portion of the recipe to make just enough for your sheet cake. To create the look pictured, use a spoon or butter knife to swirl the frosting around on top of the cake, then add some sprinkles to tie it all together. Totally quick and failproof!

how to bake a sheet cake

If you’d rather get more elaborate with your sheet cake decorating, feel free to use piping tips and creative cake decorating techniques to create what you’re imagining! This floral sheet cake tutorial shows how to create one of my favorite sheet cake looks: 

Make Ahead and Storage Tips

You can bake the sheet cake ahead of time and store it in its dish at room temperature, covered tightly with plastic wrap, a day or two ahead of frosting. Once it’s frosted, the buttercream will preserve the cake underneath and keep it moist. I still recommend covering it with plastic wrap while you’re storing it (especially after cutting into it) because the extra protection helps keep it fresh for 3-4 days. 

how to store a sheet cake

You can keep your cake in the refrigerator as an alternative to room temperature, but I only recommend that if your kitchen environment is warmer than 70ºF. If you do refrigerate your cake, be sure to bring it back to room temperature before serving it because cake tastes best at room temp!

how to convert layer cake recipes to sheet cakes

I’m so excited to provide you with lots of fun cake recipes for you to try as sheet cakes! Let me know which ones you try in the comments section, and be sure to tag @sugarandsparrowco on Instagram to show me how you decorated. I love to see what you’re caking. Stay safe and healthy out there, everyone! 


  1. Thanks for this post! I had planned for months to make the milk and cereal cake for my husband’s birthday party but now that it will only be the two of us, it seemed a bit much to make a large three-layer cake. A sheet cake will be perfect!

  2. Thanks so much for these tips! This will be perfect for my daughter’s quarantine birthday.

  3. Shannon

    Hi I’m making my nephews birthday cake in July and was wondering how I would convert the chocolate cake recipe for a cake tin in the shape of a ‘3’ its 31.5 x 20.5 x 5cm ‍♀️

    • Hi Shannon! That’s a great question. Does the tin say how many cups of batter you need to fill it? To be on the safe side, you could always 1.5x or 2x the chocolate cake recipe to ensure you have enough.

      • Hi Whitney! I’ve only just seen your message sorry about that. The cake tin doesn’t specify the amount of batter. I was planning on making two layers of cake so would this mean that I would have to double the entire amount again or would this amount of cake batter be enough for two layers?

  4. I believe doubling the recipe should be enough for two layers, but I’m not entirely sure since I’ve never baked a cake in a tin that is shaped like a number. The only way to truly tell is to double the recipe and see if it’s enough. If you need more, you can always whip up another batch while the first layer is baking.

  5. If you were to make your s’mores cake into a sheet cake, how would you go about frosting it when there are 3-4 different toppings in the recipe? I wanted to do the layer cake to get all those flavors but won’t have time.

    • Hi Ann! You could either torte the sheet cake into two layers and fill it that way, or omit one of the buttercream recipes and frost the cake with the buttercream of your choice, drizzle with chocolate ganache, and add piped meringue on top.

  6. Shannon

    Hi I’m looking to do your vanilla cake recipe with vanilla buttercream but for an 8″ Square Cake for 20 people. What recipe would work best for this shape of cake please?

    • Hi Shannon! Are you making one or two layers? If you’re making two layers, I would use the vanilla cake recipe as-is. If you’re only making one, I would half the recipe. Hope that helps!

  7. Thanks for the tips! I’m baking a cake using an 11×15 in pan and using 6 inch circle cutters to cut out the layers. Any recommendations for how high to fill the pan and bake time?

    • Hi Leslie! I would fill the pan no more than half full. I’ve never baked a cake in that size pan before but from a quick Google search it looks like it would take 15-20 minutes at 350. That’s where I’d start. Hope that helps!

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