01 - Line a 9x13-inch baking sheet with parchment paper, ensuring the edges are fully covered.
02 - Evenly arrange the banana slices in a single layer across the parchment, slightly overlapping them to create a solid base.
03 - Combine the chopped chocolate and coconut oil in a microwave-safe bowl. Microwave in 20-second intervals, stirring after each burst, until the mixture is smooth and fully melted. Alternatively, melt gently using a double boiler over simmering water.
04 - Pour the melted chocolate evenly over the arranged banana slices, using a spatula to spread and cover the entire surface.
05 - Immediately sprinkle the roasted nuts, mini chocolate chips, shredded coconut, and flaky sea salt over the wet chocolate layer before it begins to set.
06 - Transfer the baking sheet to the freezer and chill for at least 1 hour, or until the chocolate is completely firm to the touch.
07 - Remove from the freezer and break the chocolate banana slab into uneven bark pieces by hand or with a knife. Serve immediately or store in an airtight container in the freezer.