Originally posted at: http://www.mommyknows.com/how-to-rainbow-cupcakes-in-a-jar

Step 1: What You'll Need

Preheat oven to 350f

What you'll need:

1 boxed white cake mix
1 can of white frosting
variety of Wilton icing colours
12 125ml (4oz) canning jars
Sprinkles

Step 2: Step 1:

Make the white cake as per the instructions on the box. Then divide the cake mix up into portions (you don’t have to be exact). Add colouring to the cake mix. I used: No Taste Red, Lemon Yellow, Teal, Royal Blue and Violet (most of the colours of the rainbow).

Step 3: Step 2:

Add about 1 tsp of each colour into the canning jars. Place the canning jars on a cooking sheet with about 1/4″ of water on it. Bake in the oven at 350f for 25-30 minutes.

Step 4: Step 3

Remove from oven and let them cool completely.

Once cooled remove the tops of the cupcakes to make room for frosting. Ice the cakes with the frosting and top with sprinkles.