Preheat your oven to 350°F and line baking sheets with parchment paper and set aside.
In a medium saucepan, melt the butter over medium heat. Stir occasionally until the butter foams, turns golden brown, and smells nutty (about 5-6 minutes).
9 tablespoon butter
Remove from heat and pour into a heatproof bowl. Allow it to cool to room temperature (about 15 minutes).
In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.
1 & ¾ cups all-purpose flour, ½ teaspoon baking soda, ½ teaspoon baking powder, ¼ teaspoon salt
In a large mixing bowl, combine the cooled brown butter, granulated sugar, and brown sugar. Beat until smooth and creamy.
⅓ cup granulated sugar, ½ cup light brown sugar
Add the egg, the vanilla extract and miso paste until fully incorporated.
1 large egg, 1 ½ teaspoon vanilla extract, 2 & ½ tablespoon white miso paste
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the chocolate chips gently, being careful not to overmix.
4 oz semi sweet chocolate bar
Scoop the chilled dough into balls 2 tablespoons each and place 2 inches apart on the baking sheets. Sprinkle each dough ball with a pinch of flaky sea salt, if desired.
Flaky sea salt
Bake for 10 minutes, or until the edges are golden brown and the centers look just set.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.