01 - Line a baking sheet with parchment paper and set aside.
02 - Peel the bananas and cut them into ¼-inch thick coins. Arrange the slices in a single, slightly overlapping layer on the prepared baking sheet to form a rough rectangle.
03 - Place the chopped chocolate in a microwave-safe bowl and heat in 20-second bursts, stirring between each interval, until completely smooth and glossy.
04 - Pour the melted chocolate evenly over the arranged banana slices, using a spatula to gently spread and cover every piece.
05 - Drizzle peanut butter over the chocolate layer if desired. Sprinkle chopped roasted nuts, mini chocolate chips or cacao nibs, and a pinch of flaky sea salt across the surface.
06 - Transfer the baking sheet to the freezer and chill for at least 45 to 60 minutes, or until the bark is completely firm and set.
07 - Remove from the freezer and break or cut the bark into irregular pieces. Serve immediately while still cold for the best crunch and texture.