There are only a few ingredients for the actual cake:
- 2 boxes of white cake mix (any brand)
- 24 oz. of clear diet soda (2 cans, I used Sprite, but you can use ginger ale as well)
- Gel Food Coloring (Betty Crocker Classic - gel food colors)
Step 2: Divide the cake mix into 6 separate bowls as evenly as possible. By estimate, approximately 1 cup and 2 tablespoons per bowl.
Step 3: Stir color into each bowl with its own spoon.
Step 4: Measure out 2/3 to 3/4 of your first mix (about 1 cup) and pour it into the middle of the cake pan. Start with red, then orange, then yellow. In your second pan, work backwards...start with purple, then blue, then green. This is so the layers are even. After you've done the first three colors in each pan, continue with the rest of the rainbow. Pan #1 - rainbow order, Pan #2 - reverse rainbow order.
Step 5: Bake the cake according to the instructions on the box. Note: you probably need extra time (5 or 10 minutes) because of the density of the soda. The cake is done when a toothpick inserted into the center comes out clean!
Step 6: After the cakes have cooled, place one upside down on top of the other and frost! Then enjoy!
This is an easy cake for a rainbow themed birthday party of any fun affair. You could even make it with only red, white and blue for a 4th of July or Memorial Day party! Or various shades of green for St. Patrick's Day! So fun!