Step 1

Preheat the oven to 350 F. Line an 8-by-8-inch baking pan with parchment paper on all sides and set aside.

Step 2

In a small saucepan over medium-low heat, add the butter and cook, occasionally stirring with a whisk, until the butter melts completely. Remove the saucepan from the heat. Add the cocoa powder and vanilla extract and whisk until no lumps of cocoa remain. Set aside.

Step 3

In a stand mixer fitted with the whisk attachment, combine the brown sugar and eggs and whisk until the mixture turns light and pale in color and when you smoosh a little batter between your fingertips, you can no longer feel any granules of sugar, about 3 minutes. With the mixer on low speed, slowly pour the butter and cocoa mixture into the egg mixture and mix until just incorporated.

Step 4

Remove the bowl from the stand mixer and use a silicone spatula to fold in the flour and salt until no streaks of flour remain, being careful not to overmix the batter. Fold in the chocolate chips.

Step 5

Pour the batter into the prepared baking pan, spreading it evenly to the edges. Bake until the surface is shiny, the edges are set and a butter knife inserted into the center comes out mostly clean (a crumb or two attached is OK), 25 to 30 minutes.

Step 6

Place the pan on a cooling rack and allow the brownies to cool completely in the pan. Use the parchment paper to lift the brownies from the pan, then transfer the brownies to a cutting board, cut into squares and serve.