You Will Need:
Duncah Hines French Vanilla Cake Mix.
The amount of cake mix depends on the size you want your rainbow cake to be. Remember, you will be dividing your batter into 6 bowls, or 7 if you make the Indigo color.
You want your layers to be thin. I’ve posted step by step photos showing all the layers but this was a large cake. I would think for a 8 or 9 inch cake, 2 boxes would be plenty, if you divide them out equally. You have to bake one layer at a time, or more depending on how many you can put in your oven at the same time.
Follow your cake mix directions and then add 1 Tablespoon Wilton Meringue Powder to the dry cake mix before adding the water, eggs and oil.
One your cake batter has been made, divide into 6 bowls. I use Wilton gel food coloring as this does not leave an after-taste like the liquid dyes do. You want to make your colors vivid and bright. Remember, the colors will get even darker after the cake is baked.
Once you have your batter divided and colored with gels, your ready to start baking! Since the layers will be thin, you will not have to bake them as long. For an 8 or 9-inch cake, you might bake it for 15 minutes, but please check often as each oven is different, and for a larger cake, you may have to bake 20 minutes…but, check it ofen.
Gel food coloring in Red, Orange, Yellow, Green, Violet and Indigo (I use Wilton’s Gel, sold at Michael’s and Wal-Mart, but you can find Wilton products at other stores.
- Indigo (combination of black and purple (bluish purple)
1/2 cup butter (room temperature)
3 and 1/2 cups sifted confectioner sugar
3 to 4 Tablespoons light cream or milk
1 and 1/2 teaspoons vanilla or clear vanilla extract
1 Tablespoon meringue powder (Wilton) (optional)
In a medium bowl, mix butter with sugar, 3 Tablespoons cream or milk and vanilla and cream until smooth and creamy. Sift meringue powder and confectioner sugar together and slowly add to creamed mixture and mix until light and fluffy.