Lay a silicone mini muffin tray onto a medium, flat baking sheet.
Melt your chocolate in the microwave in 30 second increments, stirring in between, until completely melted, then stir in coconut oil. Alternately, you may use a double broiler method.
Add about 1 tsp of melted chocolate to the bottom of each cup and using a silicone brush up the muffin slots to cover the bottom and all the way up to the sides.
Freeze for 10 minutes to set.
Then, add in a banana slice and top with 1 tsp of peanut butter for each chocolate cup. Freeze that for 10 minutes.
Cover the cups completely with remaining melted chocolate.
Freeze until set, about 1-2 hours.
Keep the chocolate cups frozen until ready to eat, and take them out of the freezer 5 minutes before serving.