Step 1: Melt the candy melts or chocolate in the microwave in 30-second increments, stirring until completely smooth.
Step 2: Place a tablespoon of chocolate into each silicone mold cavity and spread evenly up the sides with a brush; chill for 5 minutes.
Step 3: Apply a second thin coat of chocolate to the sides of the mold if needed to ensure a sturdy shell, then chill again.
Step 4: Crumble the cake and mix with frosting until it reaches a dough-like consistency.
Step 5: Slide the popsicle sticks into the mold slits, then fill each cavity with the cake mixture, leaving room at the top.
Step 6: Top with remaining melted chocolate to seal the backs, scrape off excess, and refrigerate for 30 minutes before carefully demolding.