I made this cake for my niece's second birthday party. You can find more detailed instructions about how to actually make the cake a rainbow here, but it really is as simple as the top photos look - you dye the cake batter, layer the cake and bake! I used two boxes of Dunkin Heinz white cake box mix (but you can very well make your own white cake from scratch!) And Wilton gel food dyes to dye the cake.
This cake was so much fun to make and eat! I love the surprised look on peoples faces when you pull out the first slice ~ Rainbow cake is something that makes everyone smile :)
But for me the best part of cake is the frosting. Here is the recipe I used:
Swiss Meringue Buttercream
- 5 large egg whites
- 1 cup plus 2 tbsp. white sugar (I used vanilla sugar)
- pinch of salt
- 1 lb. (4 sticks) unsalted butter, room temp - cut into tablespoons
- 1 1/2 tsp. vanilla extract
1. Combine egg whites, sugar, and salt in a heatproof bowl of your stand mixer over a pot of simmering water.
2. Whisk constantly by hand until the sugar dissolves (~160 degrees with an instant read thermometer)
3. Attach the bowl to you stand mixer, Starting on low and increasing to medium-high speed, whisk until stiff peaks form and pan is cool (about 10 minutes)
4. Set mixer to medium-low speed and add butter, one tablespoon at a time - mixing well after each addition. Add vanilla.
5. Switch to paddle attachment and mix on low speed for 2 more minutes.
Frosting Source: Martha Stewart Cupcakes
Cake inspiration from: Ominomicon