Prepare cake, bake and cool completely. Crumble cake into the smallest pieces that you can in same pan.

Add container of frosting and mix completely. Spread evenly in the same pan.

Melt candy coating in microwave or double boiler. Immediately spread over cake mixture evenly. It will be a thin layer, you don't want it to crack too much when you cut it. Put it in the freezer for about 1/2 hour to harden everything. Cut into squares.