12tablespoonsunsalted buttercut into 1-tablespoon pieces
1/2cupunsweetened cocoa powder plus more for dustingsee Notes
1-1/4cupspacked dark brown sugarsee Notes
4large eggs
3/4teaspoonKosher salt
3/4cupall-purpose flour
1/2cup(3 ounces) bittersweet chocolate chips (60 to 70%)
Instructions
Preheat the oven to 325°F. Mist a 9-inch springform pan (see Notes) with cooking spray and line the bottom with a round of kitchen parchment.
In a medium saucepan over medium-high, cook the butter, stirring, until the milk solids at the bottom are browned and the butter has a nutty aroma, 1 to 3 minutes.
Whisk in the cocoa and sugar into the browned butter. Transfer to a medium bowl and let cool until barely warm to the touch, about 10 minutes.
One at a time, whisk the eggs into the cocoa-sugar mixture, followed by the salt and then the flour.
Add the chocolate chips and stir until evenly distributed.
Spread the batter evenly in the prepared pan.
Bake until the edges of the cake spring back when lightly pressed, 30 to 35 minutes.
Cool in the pan for 30 minutes, then remove the pan sides.
Serve dusted with cocoa powder.
Notes
You can use either Dutch-processed cocoa or natural cocoa works, just be sure it is unsweetened.
You can use light brown sugar in place of the dark brown sugar.
If you don’t have a 9-inch springform pan, you can use a 9-inch cake pan.