Line a plate or baking sheet with parchment paper. Place banana bread chunks on the parchment paper and place in the freezer while you prepare the chocolate.
In a microwave or double boiler, melt chocolate and coconut oil together. Remove banana bread chunks from the freezer and dip into the chocolate using a fork or other dipping tool. Turn the bread to coat completely in chocolate and return to the parchment lined sheet. Place the sheet in the refrigerator or freezer until the chocolate is set. Transfer the chunks to an airtight container and store in the refrigerator or freezer until ready to serve, microwaving briefly if desired.