Rainbow Cake in a jar

Ingredients:

• 1 Betty Crocker Super Moist white cake mix
• 1 Tub Betty Crocker Whipped Ready to Spread white frosting
• 3 egg whites (for cake mix)
• 1/3 cup vegetable oil (for cake mix)
• 1 1/4 cup water (for cake mix)
• Betty Crocker NEON food colors in neon pink, neon blue and neon purple
• Regular food colors in yellow, green, red and blue
• 3 (1-Pint) wide-mouth glass canning jars
• Non-stick cooking spray

Directions: 

1. Preheat oven to 350 degrees. Wash canning jars and dry thoroughly. Set lids and rims aside. Spray inside of each glass jar with a generous amount of non-stick cooking spray.
2. Make cake batter according to directions on cake mix box.
3. Divide batter evenly between 5 bowls (approximately 1 cup of batter in each bowl).
4. Add 15 drops of neon pink food coloring to the 1st bowl. Stir to blend well.
5. Add 14 drops of regular yellow food coloring to the 2nd bowl. Stir to blend well.
6. Add 24 drops of regular green food coloring to the 3rd bowl. Stir to blend well.
7. Add 7 drops of neon blue food coloring to the 4th bowl. Stir to blend well.
8. Add 8 drops of regular red + 7 drops of regular blue + 3 drops of neon purple food coloring to the 5th bowl. Stir to blend well.
9. Spoon about 1/4-cup of each color batter into each of the jars, layering the colors in this order: purple (first), blue, green, yellow, pink (last). Use a paper towel to wipe any spills or drips from the jars.
10. Place the jars in a glass baking dish. Add 1/4" of water to the bottom of the dish surrounding the jars. Bake for 35-40 minutes. Cake tops should spring back to the touch when done, but don't bake so long that the cakes are brown. You can also use a long bamboo skewer to test doneness if you have one.
11. Allow cakes to cool completely, about one hour, before frosting.
12. Spread frosting over top of cake and decorate as desired.