First, prepare the chocolate shell. Place chocolate chips in a microwave safe bowl, and heat in 30 second increments until smooth and creamy.

Grab your chocolate molds, and use a spoon to coat each mold with chocolate. Be sure to get in all the crevices and corners, and go all the way up to the edges. Place in the fridge to set when done.

Once the first layer of chocolate has set, repeat the same process one more time. Place back in the fridge to set again.

While the chocolate is setting, prepare the cake mixture. Use your hands or a fork to crumble up cooled cake or cupcakes. Start by adding in 2 tablespoon of frosting and see how the texture is. You want it to be smooth and creamy but not too mushy. Add more frosting as desired and mix well. The cake mixture should hold its shape when pinched between your fingers.

Now, it is time to fill. Add the cake and frosting mixture to your set chocolate molds. Fill about ⅞ of the way - you need a small margin at the top to seal your chocolate gems.

Grab your melted chocolate one more time (you will likely need to re-melt at this point, that's ok) - spoon some chocolate on top of each mold and use an offset spatula or butter knife to smooth it out. Try your best to make sure the bottom is very smooth and flat, and scrape off any excess chocolate. Refrigerate one more time to set, for a good 20-30 minutes.

Once the gems have completely set and hardened, gently remove them from the silicone molds. Decorate the tops of your cake gems as desired with additional chocolate and sprinkles. Enjoy!!