1 ½ sticks (12 tablespoons) unsalted butter, softened
2 teaspoons vanilla extract
1 cup packed brown sugar
½ cup granulated sugar
1 tablespoon white miso
1 whole egg plus 1 egg yolk, at room temperature
2 cups all-purpose flour
½ teaspoon baking powder
¼ teaspoon baking soda
4 ½ ounces dark chocolate
2 tablespoons dark brown miso
Smoked flaky sea salt, for topping
Directions
In a large mixing bowl, use a wooden spoon to beat together the butter, vanilla, and sugars until well combined.
Add the egg, egg yolk, and white miso. Mix until fully incorporated.
In a separate mixing bowl, whisk together flour, baking powder, and baking soda until well combined.
Mix the wet and dry ingredients until just combined.
Roughly chop the dark chocolate, then set aside a small handful to use for topping the cookies.
Stir the remaining chocolate chunks into the cookie dough until well distributed.
Add dollops of dark miso to the dough. Use a knife or chopstick to gently create swirls, being careful not to over-combine.
Scoop small mounds of cookie dough onto parchment-lined baking trays, spacing the cookies at least 4 inches apart. Top with the reserved chocolate chunks and freeze for an hour (or refrigerate overnight).
Preheat the oven to 350 F.
Transfer the cookies to the oven and bake for 12-15 minutes. Optional: As soon as you remove the cookies from the oven, bang the cookie trays on the counter 2 or 3 times to create a rippling effect.
Sprinkle each warm cookie with flaky salt and let cool on the baking trays before transferring to a wire rack and serving.