Chop the dark chocolate into small pieces and place it in a medium heatproof bowl. Add cocoa and espresso powder. Set aside.

Melt the unsalted butter in a saucepan over medium heat, stirring until golden brown. Pour over the chocolate mixture and stir until smooth.

Preheat oven to 350°F (175°C). Line a 9x9-inch pan with parchment paper.

In a large mixing bowl, whisk the room temperature eggs, granulated sugar, brown sugar, and white miso paste for about 5 minutes until thick and pale.

Gently fold the chocolate mixture into the egg mixture until combined, then add flour and fold gently until no flour spots remain.

Pour batter into the prepared pan and bake for 23-25 minutes until shiny on top and barely jiggly.

Cool the brownies in the pan on a wire rack before slicing.