Cake mix is added right into these Funfetti Cake Batter Rice Krispie Treats, along with a heap of sprinkles! You will not miss that these are a birthday cake-themed treat. A layer of melted white chocolate to top them off is icing on the cake. ;)
In a large pot over medium-low heat, melt the butter.
Add vanilla and marshmallows, and continue cooking and stirring until marshmallows are mostly melted and smooth.
Stir in cake mix.
Stir in Rice Krispies.
Fold in 1/2 cup sprinkles. Do not overmix - colors will start to muddy if you stir the sprinkles too much! Just fold them in quickly, and don't overmix!
Press mixture evenly into the bottom of a lightly buttered 13x9-inch pan.
Allow to set.
In a small saucepan over low heat, combine the white chocolate chips and shortening.
Cook and stir until melted and smooth.
Spread in an even layer over the Rice Krispies mixture.
Sprinkle with remaining sprinkles.
Allow to set. Cut into bars.