Step 1: Bake the cake according to the package instructions in a 9x13 inch pan and allow it to cool completely at room temperature.
Step 2: Once the cake is cool, crumble it into a large bowl using your hands or a food processor until you have fine crumbs with no large pieces.
Step 3: Add the buttercream frosting to the crumbs and mix thoroughly until the mixture reaches a dough-like consistency that holds its shape.
Step 4: Using a tablespoon or small cookie scoop, portion out the mixture and roll into smooth 1-inch balls.
Step 5: Place the cake balls on a parchment-lined baking sheet and refrigerate for at least 30-60 minutes to firm up.
Step 6: Melt a small amount of candy melts in the microwave. Dip the tip of each lollipop stick into the chocolate and insert it halfway into a cake ball.
Step 7: Return the pops to the refrigerator for 15 minutes to let the 'glue' set.
Step 8: Melt the remaining candy melts in a deep cup. Dip each cake pop vertically until fully submerged, then gently tap off the excess chocolate.
Step 9: Add sprinkles immediately before the chocolate sets and place the sticks in a cake pop stand or styrofoam block to dry.