Melt the chocolate chips in the microwave for 1 minute, stirring after 30 seconds. Spread it on a wax paper lined baking sheet. Stick the baking sheet in the freezer for about 15 minutes, or until set.
Melt the white chocolate chips in the microwave on 30 second increments, stirring each time, until melted completely. Or, if you are like me, melt the white chocolate in a double boiler. I have terrible luck with burning melting white chocolate in the microwave.
Using a whisk or electric mixer, beat the cake mix into the white chocolate. Let cool for a few minutes. Take the baking sheet out of the freezer & spread the white chocolate/cake batter mixture over top. Sprinkle on the sprinkles, and press down a little with a spatula. Stick it back into the freezer for about 20 minutes.
Cut into slices, or just break apart. Store in the refrigerator to keep it from melting.