Preheat your oven to 150°C (300°F). Line a baking tray with parchment paper.
In a bowl, mash the bananas until smooth. Add maple syrup, melted coconut oil, and vanilla. Mix well.
In a separate large bowl, combine the oats, walnuts, pecans, cinnamon, nutmeg, and sea salt.
Pour the wet mixture into the dry mixture and stir until everything is fully coated.
Spread the mixture flat across the baking sheet — the flatter it is, the crispier it becomes.
Bake for 20 minutes, remove from the oven, stir well, spread again, and bake for another 20–25 minutes until golden.
Let it cool completely, then stir in the optional add-ins.
Store in an airtight jar.