First, combine hot brown butter, bittersweet chocolate, and espresso powder to both melt the chocolate and cool the butter.
Vigorously whisk in eggs and vanilla to help emulsify the brownie batter.
Sift in the whole wheat flour, cocoa powder, and salt and gently fold to combine. Then mix in 90% extra dark chocolate, chopped
Pour the brownie batter into a prepped pan and bake. *PRO TIP - chill the batter overnight to enhance the flavor
Once the brownies have cooled, sprinkle with flaky sea salt, slice, and enjoy!