Put Cake Mix in a medium size microwave safe bowl.

Add Powdered Sugar and mix together.

Add milk and butter. Do Not Stir.

Put in microwave for (2) minutes. Stir immediately after taking out. Stir until completely combined.

If batter is runny add 1 Tbsp of cake mix at a time until it thickens. If it is too thick add 1 Tbsp of milk at a time until it thins out some.

Add sprinkles. If you use rainbow sprinkles do not over mix the batter or the dye will run.

Put in a 6x6 greases pan or do a double batch for an 8x8 pan.

Chill for an hour. Then cut into desired size.

I've tried this with both white and strawberry cake mix and they came out good. Try to mix it up and try new flavors.