Top banana slices with a thin layer of nut butter (about 1 teaspoon per slice). Add bananas to a plate or tray and freeze for ten minutes.
Melt chocolate until smooth. I melted mine in 3 30 second intervals in the microwave.
If using paper liners, add them to a muffin tray. If using silicone muffin liners or a silicone muffin tray you can skip that step.
Add about ½ tablespoon of chocolate to each liner. Add bananas on top of chocolate adding one banana per liner. Pour over the remaining chocolate to mostly cover bananas, about 1-2 tablespoons per cup. Top with flaky sea salt if desired.
Freeze banana bites for about 30 minutes or refrigerate for 1 hour, until set. Dig in and enjoy.