Turn a single round cake into a beautiful butterfly that’s almost too cute to eat! Printable templates and step-by-step instructions make this birthday cake a breeze.

Have you ever made a cut-up cake? It’s one of my favorite methods for making my kids’ birthday cakes. You start with a simple cake—usually a square or a round—and with a few slices and some rearranging, you end up with a whole new shape. We made these all the time when I was a kid, and they still scream birthday party to me. This butterfly birthday cake is made from just one 9-inch round cake and is perfect for a birthday celebration, a special event, or anytime you need a sweet treat.

I decorated mine using the star method because I love the look, but you can absolutely do something else: frost it smooth, cover it in sprinkles, or use candies to bring your butterfly to life. However you choose to decorate, the magic is really in the shape. And if you’re like me and can’t freehand a design to save your life, I’ve included a cutting and decorating template to guide you.

Materials

• 1 9-inch round cake
• serrated knife
• cake board
• frosting
• cutting template
• decorating template
• piping bags and couplers
• Wilton tips #18, 12, and 4

Cutting

Start by baking one 9-inch round cake. I used my usual doctored cake mix (recipe below), but any sturdy cake recipe will work here—just avoid anything too light or spongy (angel food cake, I’m looking at you!), since it can crumble when cut. 

Once the cake is completely cooled, you can either freehand the cut and cut the cake in half, then take a triangular section out from the center of both cake halves. 

If you’re worried about getting the proportions exactly right, you can use this cutting template. Just lay the template over the top of the cake, then use a serrated knife to cut along the lines. Especially with something like a butterfly where symmetry matters, I like having that extra security.

After cutting, move the halves so the cut edges face outward, and push the rounded sides together so they make a butterfly shape. Just like that, you’ve got your wings!

I like to place mine on a cake board before I decorate. You’ll need at least a 10×14 sized rectangular cake board. I actually just cut the side out of an Amazon box and covered it with foil, so you can do that too if you’re cheap like me.

Decorating

You can dip out of the tutorial here if you’re going to use a different decorating method. If you’re sticking with the stars, then you can follow along with step-by-step instructions!

I made a double batch of buttercream (recipe below) and tinted some of it for the wing decorations.

Next, I cut out the wing shapes from the decorating template, then laid them on the cake.

Once the shapes were in place, I used a Wilton #4 tip to pipe around them, careful not to pipe over them. I removed the shapes using a toothpick and was left with this:

I’m not terribly worried about the roughness of the lines, since the stars will cover them. This is just to guide me as I pipe those stars.

After that, you just fill in using Wilton tip #18. I fill in the centers of the design first, then cover the remainder. This is not difficult, but it is time consuming — fair warning!

Now, all that remains is to make the butterfly’s body and antennae. Using a Wilton #12 tip, I piped some green frosting in a circle right at the top of where the cakes meet. Then, using that same tip, I piped a long body, moving the icing downward as I went to create that elongated shape.

The finishing step is to switch to a Wilton #4 and pipe antennae on either side of the body. I added a little dot at the end of each just ’cause it’s cute!

And that’s it! A bright and happy butterfly cake from just one round. Simple, sweet, and totally charming.