This adorable Watermelon Cake is frosted with buttercream to look like a watermelon, and it actually has watermelon baked inside it!
We’ve all seen recipes for cakes made with applesauce or mashed bananas and now it’s time for a cake with watermelon in it! It’s a fun cake to bring to all of your summer celebrations!
Table of contents
- Watermelon: To get watermelon flavor into the cake, add watermelon puree instead of the water called on the cake mix box! You can also add a packet of watermelon-flavored Kool-Aid for additional flavor and color.
- Cake: This recipe uses a white cake mix plus the eggs and vegetable oil called for on the box.
- Frosting: We like using homemade buttercream frosting, but cream cheese buttercream would also be delicious! You can use store-bought frosting if you are short on time.
- Food Coloring: To tint the frosting, you need red and green food coloring or gel paste
- Watermelon Seeds: You’ll need semi-sweet chocolate chips to make “watermelon seeds.”
How To Make A Watermelon Cake
Step One: Watermelon Puree
You’ll need one cup of watermelon puree/juice for this recipe, so cut up about 1 1/2 cups of watermelon and puree it in the blender or food processor. Here’s how to cut a watermelon, as well as some very cool watermelon slicers.
Step 2: Cake Batter
For the watermelon cake batter, the ingredients are similar to those on the cake mix package, but instead of water, this recipe uses pureed watermelon.
This is what the cake batter looks like with the puree and Kool-Aid. To get a brighter watermelon color, add a dollop of red food coloring.
Grease two 9-inch cake pans and line the bottom with parchment paper. Divide the cake batter between the two cake pans, putting about two cups in each pan. Bake the cakes and cool completely.
How To Frost A Watermelon Cake
While the cakes are cooling, make some buttercream frosting (or use store-bought frosting) and tint some of it pink and some green, leaving a little of the frosting white.
Use a long serrated knife to level the cooled cakes.
Put one layer of the cake on a cake round, stand, or platter. Then, top it with pink buttercream frosting.
Top with the second cake layer and use an offset spatula to frost the outside edges of the cakes with the green buttercream frosting.
Then, frost the top of the cake with the remaining pink buttercream.
Put the white buttercream frosting in a pastry bag or large ziptop bag and cut the tip. Then, pipe a line of white frosting along the edge of the cake where the pink and green buttercream meet. Use an offset spatula to smooth out the white buttercream, if desired.
Randomly place chocolate chips, with the pointed tip downwards, on the top of the cake to look like watermelon seeds.
Make Ahead and Storage
Make Ahead: This is the perfect dessert to make ahead of time to bring to a summer party or backyard BBQ! Just be sure to keep it cool until serving time since the buttercream will melt in the heat.
Storage: Place the cake in an airtight container, or cover it in plastic wrap. Then, store it in the fridge for 3-4 days.
Frequently Asked Questions
Yes, you can make it in a 9×13-inch pan, but it will take about 3-5 minutes longer to bake.
You can substitute one cup of watermelon puree with one cup of water.
Yes, see our Watermelon Cupcakes recipe for all of the details.
More Watermelon Recipes
- Serve your friends Watermelon Salsa with tortilla chips!
- Wondering How To Pick A Good Watermelon? These are our best tips.
- Watermelon Salad is topped with homemade poppyseed dressing!
- Make Watermelon Pizza for a fun summer dessert!
- Preheat oven to 350˚F. Grease two 9-inch cake pans and line bottom with parchment paper. Set aside.
- Puree the watermelon cubes and measure out one cup of watermelon puree.
- Put the cake mix, watermelon puree, eggs, vegetable oil, and watermelon Kool-Aid (if using) in a large mixing bowl. Mix for 30 seconds on low and then beat for 2 minutes at medium speed.
- Divide batter between two cake pans.
- Bake at 350˚F for 29-33 minutes. Cool for 20 minutes in the pan, remove the cakes from the pan and then cool completely on a rack.
- Tint about 1 1/2 cups of the buttercream frosting pink, about 3/4 cup green, and leave 1/4 cup white.
- Place one cake on a cake round or cake stand. Frost top with about 3/4 cup of pink frosting. Add the second cake and frost the outside edges with green buttercream and then the top with the remaining pink buttercream. Put the white buttercream in a pastry bag (or ziptop bag) and snip the corner. Pipe the white frosting along the edge of the cake.
- Press chocolate chips into the top of the cake.