Step 1

Preheat oven to 325 degrees.

Step 2

Lightly spray a 9 x 9 baking pan with non-stick cooking spray and line with parchment paper so that it covers all four sides of the pan.

Step 3

In a medium saucepan, melt the butter over medium high heat. Stir occasionally as it melts.

Step 4

Once the butter melts, continue stirring as the butter begins to foam and make a crackling noise. Stay near the pan at this point and continue to stir often. The butter will continue to foam and then brown bits of butter will begin to form and fall to the bottom of the pan. Continue to stir until the crackling sounds stop and the butter is a rich, amber hue. Remove the butter from the heat and pour into a medium heat safe bowl.

Step 5

Immediately stir in the chocolate chips, cocoa powder and vanilla. Continue to stir until chocolate is completely melted and the mixture is shiny. Set aside to cool for 8-10 minutes.

Step 6

In a stand mixer fitted with the whisk attachment, beat together the eggs and sugar on medium speed until light and creamy, about 3 minutes.

Step 7

Once the chocolate and butter is slightly cooled, carefully stream it into the mixer while continue to beat the eggs and sugar on medium speed.

Step 8

Once all of the chocolate has been added, continue to beat for about 30 seconds until combined.

Step 9

Remove the bowl from the mixer and add the flour.

Step 10

Stir with a wooden spoon or spatula, gently folding the flour into the chocolate mixture.

Step 11

Add the additional chocolate chips, if desired. Do not over mix.

Step 12

Pour the batter into the prepared pan and smooth the top with an offset spatula.

Step 13

Bake on the center rack of the oven for 45 minutes. The brownies may puff up in the center while baking but will deflate slightly as they cool. To check for doneness, insert a toothpick into the center of the brownies. The toothpick should come out almost clean, with just a few crumbs remaining. The brownies may take up to 50 minutes to cook depending on your oven.

Step 14

Remove the pan from the oven and cool completely on a wire rack before slicing.