Preheat your oven to 175°C (350°F) and line an 8x8 inch baking pan with parchment paper, leaving overhang for easy removal.
Peel the ripe bananas and mash them thoroughly with a fork until smooth and jammy, with some small lumps for texture.
In a dry skillet over medium heat, toast the oats for 2-3 minutes until fragrant and slightly golden, stirring constantly to prevent burning.
In a large bowl, combine the mashed bananas with the nut butter and stir until smooth and well mixed.
Add the honey or maple syrup, salt, and vanilla extract to the banana mixture, stirring until evenly incorporated.
Fold in the toasted oats and any optional add-ins like dried fruit or nuts, mixing gently until everything is evenly coated and combined.
Transfer the mixture into the prepared baking pan, pressing down firmly with a spatula or the back of a spoon to create an even layer.
Bake for 20-25 minutes, until the edges are golden brown and the center feels set but still a little soft.
Remove from the oven and let cool in the pan for at least 10 minutes, then transfer to a wire rack and cool completely for about 30 minutes to set.
Once cooled, lift the bars out of the pan using the parchment overhang and slice into squares or rectangles.
Enjoy immediately or store in an airtight container at room temperature for up to 3 days, or refrigerate for up to a week.
For longer storage, wrap individual bars in plastic wrap and freeze for up to a month. Reheat briefly or enjoy chilled for a quick, wholesome snack anytime.
