2containers (about 3 cups)white or vanilla frosting
about 2cupsrainbow sprinkles
Instructions
For rainbow cake layers:
Preheat oven to 350 degrees F. Spray round cake pans with nonstick cooking spray.
In large bowl, combine cake mix, water, oil and eggs. Beat with electric mixer on low speed for 30 seconds, then on medium speed for 2 minutes, scraping bowl occasionally. Divide batter evenly among 5 bowls, about 1-1/3 cups each.
Using food colors, tint batter in separate bowls red, orange (using red and yellow), yellow, green and blue. Start with a small amount of coloring, and adjust as needed.
Pour each colored batter into separate cake pans (use one at a time if you don't have 5 pans). Set aside and cover remaining batter until ready to use.
Bake 25 to 30 minutes (depending on size of your cake pan), or until cake springs back when touched lightly in center and begins to pull away from side of pan. Cool 10 minutes. Remove from pans to cooling racks. Cool completely before frosting.
Once cake has cooled completely, slice domed top with a sharp knife to flatten. This will help you layer the cakes evenly.
For decorating:
With a flat spatula, evenly spread a thin layer of white frosting on your bottom cake layer. Top with remaining layers, spreading frosting between each.
Spread a thin layer of frosting all over the entire cake. This is your "crumb coat" (one of two frosting layers) that holds everything together. Refrigerate until firm, at least 1 hour.
Spread with remaining frosting. Coat all over with rainbow sprinkles. Refrigerate until firm and ready to serve.