Preheat your oven to 350°F (175°C) and line an 8x8 inch baking dish with parchment paper, leaving some overhang for easy removal.
In a large mixing bowl, combine the mashed bananas, peanut butter, and honey (or maple syrup). Mix until smooth and well combined.
In another bowl, combine the rolled oats, chopped nuts, dark chocolate chips (or raisins), cinnamon, and sea salt. Stir to evenly distribute the dry ingredients.
Pour the dry ingredients into the banana mixture and fold together until the mixture is well combined.
Transfer the oat mixture into the prepared baking dish. Use the back of a spatula to press it down evenly into the dish.
Bake in the preheated oven for 20-25 minutes or until the edges are golden and the center is set.
Remove from the oven and let it cool in the pan for about 10 minutes before lifting out using the parchment paper. Allow it to cool completely on a wire rack.
Once cooled, cut into bars and enjoy!
Notes
Store leftovers in an airtight container at room temperature for up to a week or in the fridge for longer freshness.