1. Start by preparing some brown butter. Add the butter to a small saucepan and heat until it melts. Let the butter cook for a few minutes – it will bubble quite a bit. The bubbles will die down at some point and the butter will start to foam up, get dark speckles at the bottom of the saucepan, and smell nutty – this means the brown butter is done. Transfer immediately to a heatproof bowl (melted butter and the brown but not black speckles from the bottom). If you leave the butter in the saucepan, it will continue cooking and might get an unpleasant burnt flavor. Set aside to cool down.

2. Add the browned butter and both sugars to a large bowl and mix for 2-3 minutes until light and fluffy. Add the mashed banana, egg, and vanilla extract and mix until very well combined. In a separate bowl mix the spelt flour with baking soda and salt. Add everything to the large bowl and mix until just combined. Add the chopped walnuts and chocolate and fold in – the dough will be very soft. Place the dough in the fridge for about 30 minutes.

3. Preheat the oven to 375°F (190°C). Line a baking sheet with baking parchment and set aside. Use a large cookie scoop* and place 4-5 dough portions with a good amount of space in between on the baking sheet. Sprinkle the dough with some additional chocolate and flaky sea salt (optional) and bake the cookies for about 11-13 minutes (the time varies from oven to oven) – the cookies will spread a lot. They are done when the edges are set with a bit of color. Take out of the oven and let cool down on the baking sheet for some time, then transfer to a wire rack and let cool down completely. Repeat with the remaining dough.