1. Line a baking sheet with parchment paper; set aside. Trim about 1/2 inch from the perimeter of the cake. Working in batches, crumble cake into the bowl of a food processor; process until fine crumbs form. Transfer to a large bowl and add frosting; blend together using the back of a spoon, until well combined, 5 to 10 minutes.

2. Roll mixture into 1 1/4- to 1 1/2-inch balls; transfer to prepared baking sheet. Cover with parchment-paper-lined aluminum foil. Transfer to refrigerator until chilled, about 2 hours or to a freezer for about 10 minutes.

3. Begin to shape balls into cupcakes by rolling balls first into logs. Fit logs into a 1 1/4-by-3/4-inch flower-shaped cookie cutter. Push cake mixture into the cutter halfway so that some of the cake mixture extends beyond the top of the cutter. Shape extended cake mixture into a cupcake-shaped top. Push cake from cutter to remove. Transfer to a parchment paper-lined baking sheet. Transfer to freezer until chilled, 5 to 10 minutes.

4. Meanwhile, melt chocolate in heatproof bowl set over (but not touching) simmering water. Line another baking sheet with parchment paper; set aside. Remove cupcakes from freezer and dip the bottom of each cupcake into the chocolate; transfer, bottom-side up, to prepared baking sheet. To make lollipops, insert a lollipop stick into the bottom of each cupcake. Let chocolate set, 15 to 20 minutes.

5. Melt white chocolate or pink candy melts in heatproof bowl set over (but not touching) simmering water. Dip the tops of the cupcakes into the chocolate and place right-side up on prepared baking sheet or stick lollipop sticks into a Styrofoam square. Place a candy-coated chocolate in the center of each and top with sprinkles. Let dry completely.