Anne Cortz

To make this Kirby-themed rainbow cake for a birthday party, I made two types of cake. One is the base cake, which is basically a white cake colored with food colors to resemble a rainbow, and the other is a chocolate mud cake baked in hemisphere molds and stuck together to create Kirby’s round form. I share the two cake recipes below. I hope you have as much fun creating these tasty rainbows as I have!

The rainbow cake

For the base cake, I used a white cake. This is different from most basic vanilla cakes as this uses only egg whites as opposed to the whole egg. I learned about this from Candace Nelson’s Sprinkles cookbook, where her vanilla cupcakes omit the yolks, resulting in a cake with a more pronounced vanilla flavor. I decided to do this here to make the vanilla shine, as well as for the added bonus of having a white batter that does not conflict with the food colors. Tinting a yellowish cake light blue has nowhere to go but green-ish.

The recipe below is derived from a Martha Stewart recipe for white cake. Scroll further down for the chocolate mudcake recipe and more notes about the cake decoration.

Rainbow Cake

A white vanilla cake for the perfect rainbow canvas.

• 375 g all-purpose (plain) flour (, dry (ingredient))
• 10 g baking powder (, dry)
• 6 g salt (, dry)
• 245 g milk (, wet)
• 3 g vanilla extract (, wet)
• 335 g unsalted butter (, room temperature)
• 450 g white sugar
• 8 large egg whites (, around 264g)

1. Grease 3 round 8-inch cake pans and line the bottom with baking paper.

2. Preheat oven to 350℉ or 175℃.

3. Add all dry ingredients together. Sift or mix with a wire whisk making sure there are no lumps.

4. On another bowl, combine wet ingredients.

5. Beat butter and sugar using the paddle attachment of your mixer on medium speed, until pale and fluffy.

6. Add 1/3 of the dry ingredients, mix for a few seconds until incorporated. Do not mix too long on any stage as the flour will cause the cake to toughen.

7. Add half of the wet ingredients and mix just until incorporated.

8. Repeat the steps above- add 1/3 of the dry ingredients, mix, then the 2nd half of the wet.

9. Finally, mix in the rest of the dry ingredients.

To add the colors

1. Divide batter into 7, or to however many colors you want. Ideally, you will want to have more batter on the outer color (red) and less batter for the inner color (violet). While this is optional, this will result in a more balanced looking rainbow.

   
   
   

2. Bake for 25-30 minutes or until a toothpick inserted comes out clean.

The chocolate mud cake

For the round Kirby character on top, I decided on a dense chocolate mud cake to hopefully make the assembly easier. To make a round cake, you will need two cakes baked in hemisphere molds, which is simply a round-bottomed cake tin that makes up half of the round cake.

The two hemisphere cakes are then fused together with a thick layer of chocolate ganache, made with three parts chocolate to 1 part cream (3:1), for instance, 300g melted chocolate and 100g cream. I used milk chocolate as this may appeal more to the kids who will be eating the cake. I also use this ganache to cover the outside of both the Kirby and the rainbow cake, while my chocolate filling for the rainbow cake is a softer 2:1 ganache.

This Kirby Rainbow Cake is fondant covered and decorated. The round cake is an interesting challenge to cover smoothly in fondant. I thankfully was able to manage to make it smooth on one side, however the other was as wrinkly as a prune, conveniently covered in cut-out stars. Here’s a useful video on how to do it.

The below chocolate mud cake recipe is inspired from the recipe I learned from Chef Aggy Villabona when I took her Fondant Cake 101 class at the Heny Sison Culinary School.

Chocolate Mud Cake

Dense, moist chocolatey cake.

First Group

• 130 g unsalted butter
• 110 g dark chocolate
• 2 large eggs
• 225 g white sugar

Dry Ingredients

• 125 g all-purpose / plain flour
• 25 g cocoa powder
• 1.25 g baking soda (, around ¼ tsp)

Last Group

• 77 g hot water
• 12 g coffee powder (, optional (omit for kids))
• 50 g condensed milk
• 2.5 ml vinegar (, around ½tsp)

1. In a cup, stir condensed milk and vinegar. Set aside.

2. In a microwave or over a bain-marie, heat butter until melted.

3. Stir in chopped chocolate into the hot butter and sit for 1-2 minutes until chocolate has also melted. If needing more heat, microwave in 10-second bursts. Alternatively, heat over a bain marie.

4. Whisk in eggs and sugar.

5. Add your dry ingredients: flour, cocoa powder and baking soda. Whisk just until incorporated.

6. Add the last group: condensed milk-vinegar mixture, coffee powder and hot water. Mix until you get a smooth batter. Do not overmix.

Dessert

cake, chocolate

Looking for your next sweet bake? How about these fudgy Coconut Revel Bars for a fun treat?