This kids rainbow birthday cake was made for our baby girl who turned 1 more than a year ago. Creating a rainbow birthday cake meant more than just the fun of it. Our baby was born with gastro-oesophageal reflux, thus our first few months with her were a nightmare – constant crying, no sleep and all that. The day she turned 1 simply reminded all of us that ‘A rainbow comes out after every storm’. Maybe a bit cheesy, but that’s really how I felt, which is why her first birthday theme just had to be Rainbows.
I decided to share this kid friendly recipe after more than a year of making it, because of the positive feedback I got about it from friends. It is relatively easy to make – easy enough for my 7-year-old daughter to help in making it. So it could very well be turned into one of your kids activities at home during the school holidays. But the best part about making this kids rainbow birthday cake is cutting the first slice and revealing the colorful layers within.
The recipe below is for a 6 layer rainbow cake baked in a 10 inch diameter cake pan. Make sure to use large mixing bowls for this recipe. For a smaller cake, halve the quantity of the ingredients, and use an 8 inch cake pan, possibly making only 4 cake layers.
Ingredients for the kids rainbow birthday cake:
- 4.5 cups cake flour
- 3 cups granulated sugar (or caster sugar)
- 2 tablespoons baking powder
- 2 teaspoons salt
- 1.5 cups cold water
- 1 cup canola oil
- 10 eggs, separated
- 2 tablespoons vanilla extract
- 1 teaspoon cream of tartar
- Food coloring
Ingredients for the white icing:
- 1 block of cream cheese, softened
- 1/2 cup sugar
- 1L. cream
- 420g. melted white chocolate
Method for the kids rainbow birthday cake:
Preheat the oven to 160 degrees Celsius (or 325 degrees Fahrenheit).
1) Combine the flour, 2 cups of sugar, baking powder, and salt in a bowl. Mix till well combined. Pour in the cold water, canola oil, egg yolks, and vanilla extract into the flour mixture, then whisk until the texture becomes smooth. Set aside.
2) On a separate mixing bowl, combine the egg whites and cream of tartar. Beat using an electric mixer (high speed) until texture becomes fluffy. Beat in the remaining 1 cup sugar a teaspoonful at a time until combined.
3) Gradually fold the egg white mixture into the flour/egg yolk mixture, starting with approximately 1/8 of the egg white mixture followed by another 1/8 until everything is fully combined. Remember to ‘fold’ and not ‘mix’, to keep the air in the mixture.
4) Divide the mixture equally into 6 bowls. In each individual bowl, place a few drops of food coloring, folding the color into the mixture. In our rainbow cake, we used the colors: red, orange, yellow, green, blue and purple (the purple did not turn out well though, so we decided not to include this in the cake).
This is my 7-year-old daughter folding in the food coloring into the cake batter…
5) Line the bottom and sides of a 10 inch round cake pan with baking paper. Pour in the batter of one of the 6 bowls. Bake for 20 minutes. Repeat this process for the remaining 5 layers.
Note: You can make the kids rainbow birthday cake layers in advance. Just make sure to let the layers cool down, wrap it tightly with cling wrap, and freeze until needed. Upon assembly, make sure to thaw the rainbow cake layers in room temperature for approximately 2 hours, before icing it.
Method for the white icing:
Mix 1 block of softened cream cheese and 1/2 cup sugar.
Pour in 1L. cream and whip with electric beater until stiff.
Fold in 4200g melted white chocolate.
Assembly of the kids rainbow birthday cake:
Place one colored layer on a 12 inch cake board. I started with blue, just to try to stay true to the colors of the rainbow, with red being on top. Spread a thin layer of icing on top. Then top with another colored layer. Alternate icing and cake layers. After all layers have been put in, spread the icing on the top and sides of the cake. And now you’re ready for cake decorating!….
Decorating the kids rainbow birthday cake:
I wanted to keep the outer decor of the cake simple, so we simply scattered marshmallows on top of the cake, wrapped a thin piece of ribbon on the base of the cake and placed the special 1st birthday candle on top of the marshmallows.