Slice bananas into 1/4-inch rounds and place half of them on a baking sheet lined with parchment paper.
Spread a small amount of peanut butter onto each banana slice.
Top with the remaining banana slices to form mini sandwiches.
Freeze for 1 hour or until firm.
In a microwave-safe bowl, melt chocolate chips with coconut oil (if using) in 30-second intervals, stirring between each until smooth.
Dip half of each banana sandwich into the melted chocolate and return to the parchment paper.
Freeze again for 15-30 minutes until chocolate is set. Enjoy!