You'll need flour, cocoa powder, espresso powder, salt, brown butter, vanilla, sugars, eggs, and chocolate.
Make the batter
Melt the chocolate and sugars in the brown butter. Whisk in the eggs and vanilla. Fold in the dry ingredients, then the chopped chocolate.
Spread the batter into a square pan and bake at 350 degrees F for about 34 minutes.
Cool in pan
Allow the brownies to cool in the pan completely before cutting.
Top with flaky sea salt and enjoy!