01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper to prevent sticking.
02 - In a medium bowl, whisk together the flour, baking soda, baking powder, and salt until evenly distributed. Set aside for later use.
03 - In a large bowl, beat the butter, miso, brown sugar, and granulated sugar together until creamy and smooth, approximately 2-3 minutes.
04 - Add eggs one at a time, beating thoroughly after each addition. Mix in the vanilla extract until fully incorporated.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until combined. Avoid overmixing to prevent tough cookies.
06 - Gently fold in the chocolate chips or chopped chocolate until evenly distributed throughout the dough.
07 - Scoop the dough using about 2 tablespoons per cookie onto prepared baking sheets, spacing approximately 2 inches apart to allow for spreading.
08 - Sprinkle with flaky sea salt if desired for a sweet and salty contrast.
09 - Bake for 11-13 minutes, until the edges are golden brown and the centers remain slightly soft for a chewy texture.
10 - Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely before serving.