Add chocolate chips to a microwave-safe bowl and microwave on 50% power for 60 seconds. Stir and repeat. Stir until melted completely.

Scoop 1 large dollop of chocolate into 3 of the molds. Drag the dollop on the bottom of the mold up the sides to coat evenly.

Freeze for 15 minutes. You will not use all of the chocolate for the cavities. 

Remove from the freezer and check to make sure each cavity is coated in chocolate. One way to do this is to hold it up to the window or light making sure no light shines through where you have coated the chocolate. If necessary, reheat the chocolate and add a little more, making sure the mold is solid.

Add 1 tablespoon of powdered peanut butter to each cavity and top with mini marshmallows. 

If necessary, reheat the remaining chocolate. Add it to the microwave and microwave at 50% power for 15-30 seconds and stir until smooth.

Divide chocolate into thirds and add a dollop on the top of each cavity.

Gently spread with the back of the spoon to seal shut. Top with mini marshmallows and chopped peanut butter cups.

Freeze for 15 minutes or until solid. 

Gently pull the mold away from the chocolate and press on the bottom, turning the mold inside out and removing the bomb. 

To serve: Place into a mug and pour nearly boiling milk on top of the chocolate. Stir well until melted and combined.