Buttercream Terrazzo Cake Tutorial

Terrazzo patterns seem to be everywhere these days, and I am all for it. These pretty mosaic prints were originally popularized in the early 1900’s as a trendy floor tile design. Nowadays you’ll find terrazzo prints on walls, ceramics, furniture finishes, and all the things. I’ve been dying to incorporate it into a cake design for awhile now, so when JOANN asked me to create a project for National Craft Month I knew it was the perfect time to make my terrazzo cake dreams come true! I stocked up on some essential Wilton supplies and got right to work on this beauty.

UPDATE 2025: JOANN has (sadly!!) gone out of business, so I have slightly changed these product links.

I am so, so happy with how this cake turned out! The vast majority of terrazzo cakes I’ve seen before have been made with fondant (and they do look amazing!), but since I’m such a buttercream nerd I really wanted to see if I could create the look entirely with frosting. I’m glad I challenged myself, because I figured out a technique that works so well! By creating the print with buttercream on parchment paper, I was able to transfer it onto the top and sides of my cake and get a smooth terrazzo print all over. Just imagine all the amazing color palettes this design will work with!

This terrazzo technique is super easy, but I will admit that using it on both the top and sides of the cake can be a little time consuming. It essentially involves creating large buttercream transfers (one for the top and one to wrap around the sides) and ironing them onto the cake with a fondant smoother. Most of your time is spent waiting for those transfers to firm up in the refrigerator until they’re just the right consistency to work with. If you’re short on time, using this technique on only the sides will give you that same terrazzo look while saving you half the time! Either way, this terrazzo technique is going to make your cake next level.

Here’s a quick video of the decorating process for you to visualize the technique before you read all about it below:

If you’re into cake decorating videos like this one, be sure to check out my YouTube Channel! You’ll find tons of videos to inspire you there, and make sure you never miss a new one by clicking the Subscribe button.  

You Will Need: 

• 6-inch cake that’s been crumb coated and chilled
• 1.5 batches of vanilla buttercream
• Food color gels of your choice
• Bowls and spoons for color mixing 
• Parchment paper
• Scissors
• Pencil
• A ruler and a piece of string for measuring
• 6-inch cardboard cake circle
• Wilton Tip 2 (x5) 
• Piping Bags 
• Angled Icing Spatula
• Fondant Smoother

Step 1: Create a Buttercream Color Palette

Reserve 2.5 Cups of buttercream and divide the rest evenly amongst separate bowls, one per color of your terrazzo tiles. I decided to use five different colors in my design, so I divided my buttercream into five different bowls and used the Wilton Color Right System to color each one.

The Wilton Color Right System is great for creating custom colors, and it comes with a handy chart to help you mix just the right amounts to get the color you have in mind. For example, to get the muted pink tone I mixed a little of the Pink with the tiniest bit of Brown to create more of a dusty rose color. 

Mix away until you’ve got the ideal color palette, then add each color into a separate piping bag fitted with Wilton Tip 2. 

Step 2: Measure and Cut the Parchment Paper

Before you start piping away, you’ll first need to cut out parchment paper to fit the top and sides of your cake. Measuring the top is easy if you have a cardboard cake circle that’s the same size as the diameter of your cake. Simply trace the cake circle onto a piece of parchment paper and cut it out. 

For the sides, you’ll need a ruler and a piece of string. Measure the height of your cake with the ruler, then wrap a string around your cake and mark where it comes together before measuring it with the ruler. This will give you the height and circumference of your cake’s sides. Add about ½ inch to the height measurement and 1 inch to the circumference measurement, then trace the dimensions onto wax paper and cut it out. You’ll now have a strip of parchment paper that’s sized just a tiny bit bigger than you need (trust me on this!) to create your terrazzo pattern on. 

Step 3: Pipe the Terrazzo Colors

Starting with the circular piece, use your piping bags to create random terrazzo-inspired shapes all over the parchment paper. Be sure to leave some blank spaces in between to give the shapes just the right amount of space. It helps to pull up some images of terrazzo patterns for inspiration.

Once your terrazzo tiles are piped on, place the parchment into the refrigerator to firm up for about 20 minutes. This part is important for making sure the tiles maintain their perfect shapes during the next step. 

Step 4: Frost the Parchment Paper 

When your terrazzo tiles are nice and firm, spread the reserved buttercream over top of them, creating a ¼ inch thick layer of frosting over the entire piece of parchment paper. Make sure the buttercream is as smooth as possible and don’t be afraid to apply a little pressure to help fill in all the spaces between the color tiles.

Then, place the frosted parchment pieces back into the refrigerator for another 10 minutes, but no longer. You want to make sure the buttercream is firm enough to work with, but not so firm that it doesn’t adhere to the cake easily. 

Step 5: Transfer the Terrazzo Pattern to the Top

Add a super thin layer of fresh buttercream frosting to the top of the cake to act as glue, then place the circular Terrazzo parchment on top, buttercream side down.

Use the Wilton Fondant smoother to press the parchment down so it adheres to the top of the cake perfectly, then place the cake back into the refrigerator for another 10 minutes. If you feel like the top needs to be flatter, you can put a weight (like a couple soup cans) into a cake pan that’s the same diameter as your cake and place it on top. This will keep just the right amount of pressure on it while it sets in the fridge.

After it’s firmed up, carefully peel back the parchment paper to reveal your beautiful buttercream terrazzo!

Step 6: Create the Terrazzo Pattern on the Sides

Repeat steps 3 and 4 using the strip of parchment paper you previously prepared for the sides of the cake.

After its last trip to the refrigerator, where it’s semi-set, apply a thin layer of fresh buttercream to the sides of the cake for glue.

Wrap the parchment (buttercream side down) around the circumference of the cake and be sure to pull it as tightly as you can so it makes contact with every inch of those sides. You can secure the parchment with binder clips if you need to, but mine really stayed put once I had it wrapped.

Smooth the terrazzo wrap with the Wilton Fondant smoother and place it back into the refrigerator for a final 10 minutes.

Now that the wrap is nice and set, gently peel the parchment paper off the cake to reveal those gorgeous terrazzo sides.

Finally, use a paring knife to cut away the excess buttercream around the top edge. This part is essential for making sure you’ve got perfect, sharp edges.

Just look at that pretty buttercream terrazzo transfer!

Disclaimer: I was compensated by JOANN for my work of creating this project, styling, filming, photographing, and writing about their products. As always, all opinions are honest and my own. Thank you for supporting brands that support Sugar & Sparrow.