Line a baking sheet or tray with parchment paper.
Peel the bananas and slice each one in half lengthwise. Cut each long half into two pieces to create 8 banana slabs. Arrange them on the prepared tray.
Spread about 1/2 tablespoon of peanut butter evenly over each banana slice.
Sprinkle chopped peanuts over the peanut butter and add a light pinch of flaky sea salt.
In a microwave-safe bowl, combine the dark chocolate and coconut oil. Heat in 20–30 second intervals, stirring between each, until smooth and glossy.
Spoon or drizzle the melted chocolate over each banana piece. You can fully coat the slices or lightly drizzle the chocolate for a thinner shell.
Freeze the Frozen Banana Snickers for at least 60 minutes, or until firm and fully set.
Serve straight from the freezer and enjoy.