Watermelon Cake

Even if you’re a baking novice, you can still pull off this whimsical watermelon cake, from its layered build to the cute decoration. White cake mix and store-bought frosting keep this recipe easy and quick, and frosting the cake is easy with our step-by-step images (and even a video!). This cake doesn’t just look like an adorable, summery watermelon; it tastes like one, too. The secret? A tiny bit of watermelon gelatin!

Ingredients for Watermelon Cake

• White cake mix: Look for the best white cake mix at the store. It should bake a moist cake, have a lovely vanilla scent and maintain a stark white hue so the watermelon gelatin’s pink can shine.
• Watermelon gelatin: Gelatin is the secret to all the summery watermelon flavor. Make sure you’re buying a 3-ounce package, nothing bigger or smaller.
• Eggs: Two eggs bind the cake layer ingredients together while providing structure and stability.
• Canola oil: Neutral-flavored canola oil maintains moisture in the cakes.
• Frosting: Purchase a white-hued vanilla or cream cheese frosting from the store. The inner watermelon ring needs to be white, and the other two frosting components will be dyed. You can use your own vanilla frosting or cream cheese frosting recipe if desired.
• Food coloring: Red and green food coloring will help dye the frosting pink and green. You can use liquid food coloring, but gel food coloring will create the most vibrant hues.
• Chocolate chips: We use chocolate chips to add the “seeds” to the watermelon.

Directions

Step 1: Make the batter

Preheat the oven to 350°F. In a large bowl, add the white cake mix, watermelon gelatin, water, eggs and canola oil. Use a hand mixer or stand mixer to beat them on low speed for 30 seconds. Turn the speed up to medium and beat for two minutes.

Step 2: Bake the cakes

Pour the cake batter into two greased and floured 9-inch round baking pans. Bake the cakes for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean.

Cool the cakes in their pans for 10 minutes, then remove them from the pans and transfer them to wire racks to cool completely.

Editor’s Tip: It’s important you properly grease the cake pans so they come out easily and without breaking. Don’t let your hard work go to waste!

Step 3: Prepare the frostings

Set aside 2 tablespoons of the frosting for decorating. Place 1-1/4 cups of frosting in a bowl and tint it with the red food coloring until it’s as pink or red as desired.

Tint the remaining frosting with the green food coloring until you’ve reached your desired shade of green.

Step 4: Assemble and frost the cake

Place one cake layer on a serving plate. Add a 1/2 cup of the red frosting to the center and spread it out to within 1/4 inch of the edge. Top with the second cake layer, making sure the cakes are lined up evenly on all sides.

Frost the top of the cake with the remaining red frosting to within 3/4 inches of the edge. Try to create as even a circle as possible. Frost the side and top edge of the cake with the green frosting so the red and green frosting are touching, but not mixing with one another.

Step 5: Decorate the cake

Cut a 1/4-inch hole in the corner of a pastry bag. Fill the bag with the reserved white frosting. Pipe a circle around the top edge of the cake where the green and pink frostings meet.

For the “seeds,” push the chocolate chips upside down into the cake top in the red circle.

Recipe Variations

• Add “seeds” inside: Bring the chocolate chip “seeds” inside the cake, too! As soon as you’re done making the batter, fold in a handful of chocolate chips, then portion the batter into the cake pans and bake the cakes.
• Change the frosting hues: Change the frosting’s vibrancy with more or less food coloring. It can range from delicate pale pink and green to bright red and emerald green.

How to Store Watermelon Cake

Store watermelon cake in an airtight container in the refrigerator. If stored properly, the cake will last up to five days in the refrigerator. I like to press a piece of storage wrap on any cut and exposed sides to prevent the crumb from drying out.

Can you freeze watermelon cake?

Yes, you can freeze watermelon cake. If you want to freeze the whole frosted cake, place the cake in the freezer, uncovered, until the frosting is hard, 30 to 60 minutes. Wrap the storage wrap over the cake and freeze it for up to one month. Thaw overnight in the fridge.

To freeze leftover cake slices, wrap each slice in storage wrap and place them in an airtight container. Freeze for up to one month and thaw overnight in the fridge.

Watermelon Cake Tips

Can watermelon be used in baking?

Since watermelon is mostly made up of water, it doesn’t lend itself well to actual baking. That’s why our cake utilizes watermelon gelatin for flavor. However, you can use the fruit in no-bake watermelon desserts like watermelon pie—with its whole pieces of watermelon—or homemade watermelon ice cream.

Can you use other types of gelatin to make a watermelon cake?

You can certainly use another flavored gelatin if you wish. Just be aware that whatever flavor you choose will become the main flavor of the cake. Strawberry is a great option, as it’s most similar to watermelon in terms of flavor profile and color.

My cakes baked with a dome on top. How do I cut them off?

If your cakes wound up with a dome on top, cut them off with a cake leveler or a serrated knife. A cake leveler makes quick work and is easy to use, but this one-trick pony takes up cabinet space. Even as a frequent cake baker, I always cut cake layers evenly with a serrated knife.