Prep the bananas: Peel and slice into 1/2-inch rounds. Aim for even thickness so they freeze and sandwich well.
Make banana “sandwiches”: Place half the slices on a parchment-lined baking sheet. Add a small dollop (about 1/2 teaspoon) of peanut butter to each, then top with another slice to make a bite-size sandwich.
Chill in the freezer for 20–30 minutes until firm.
Melt the chocolate: In a microwave-safe bowl, combine dark chocolate and coconut oil. Microwave in 20–30 second bursts, stirring between each, until smooth. Or melt gently over a double boiler.
Dip the bites: Working quickly, dip each frozen banana sandwich halfway or fully in the melted chocolate.
Let excess drip off, then place back on the parchment.
Finish with salt: Immediately sprinkle a pinch of flaky sea salt over the chocolate before it sets. Add any optional toppings now.
Set and freeze: Return the tray to the freezer for 30–45 minutes, until the chocolate is firm and the bites are solid.
Serve: Enjoy straight from the freezer or let them sit at room temperature for 2–3 minutes for a slightly softer texture.