Cake batter fudge: 10 minutes. You Will need: Yellow Cake Mix, Butter, Milk, Confectioners Sugar and Sprinkles./Take 1 Cup Yellow Cake Mix + 1 Cup Confectioners Sugar and place in a microwave safe bowl, mix together. Add 1/2 Stick Butter (1/4 Cup) and 1/4 Cup Milk, DON'T MIX. Microwave 2 minutes then stir. Mix in Sprinkles and pour into a greased pan. Refrigerate 1 Hour.