In a regular size muffin tin, place 12 fluted muffin liners.
In a medium, heat-safe bowl add the chocolate, shortening, cocoa powder, vanilla and sea salt and set over a medium saucepan of simmering water. Do not let the bowl touch the water or let the water come to a boil. Stir frequently until melted and smooth and then turn off the heat. Fill each muffin liner with 1 tablespoon of melted chocolate and place the muffin tin in the fridge for at least 20 minutes to set up.
In a small bowl, thoroughly blend together the powdered sugar, butter, shortening, milk and peppermint until smooth. Stir in the crushed peppermint candies until evenly distributed and set the bowl in the freezer to firm a bit. Once chilled through, roll 1 heaping teaspoon of the peppermint filling into a ball and press down to form a flat disc. Place one disc on top of the chocolate in the center of each muffin liner and then cover with an additional 1 tablespoon of melted chocolate. Tap the muffin tin on the counter to smooth the chocolate over the top. Set in the fridge for 4 minutes. Once the chocolate is not quite set (but firmed up a bit) sprinkle each cup with either crushed peppermint candy or sprinkles. Place in the fridge to firm up and set out for 5-10 minutes prior to serving.