The chocolate is too thin: It's possible your chocolate layer is too thin. Pay special attention to the bottom layer of chocolate that you paint on the mold. I like to paint 2-3 layers to ensure a thick enough layer that won't crack. If you find cracks in the chocolate after they've been removed from the cake popsicle mold, you can always dip the whole cakesicle into additional melted candy wafers to fix the cracks. The chocolate isn't at the correct temperature: Be sure to freeze the cakesicle mold in between each layer of candy wafers to allow enough time for them to set. At the same time, don't keep the molds in the freezer too long. When the chocolate gets too cold, it can make cracking easier. You're being too rough: Be sure to handle the cakesicles carefully, especially when you're pressing the cake layer into the mold.