Step 1

Heat oven to 350°F.

Step 2

Spray an 8 x8 inch baking pan with cooking spray and line bottom and sides with parchment paper. Set aside.

Step 3

To brown the butter, melt the butter in a large saucepan on medium heat. Once melted, begin stirring occasionally. The butter will begin to crackle and pop and foam will form at the top. Continue stirring. Once sizzling sound stops, continue stirring often until golden brown bits begin to collect on the bottom of the pan. The butter will smell slightly nutty and aromatic. Remove from heat. Pour the butter and the dark bits of milk solids into a large bowl. Let cool for 15 to 20 minutes.

Step 4

Meanwhile, whisk together the flours and salt. Set aside.

Step 5

Once the brown butter is slightly cooled, add the brown sugar and granulated sugar and whisk until well combined, about 1 minute.

Step 6

Add the eggs and vanilla and whisk for 1 minute. Mixture will be smooth and glossy.

Step 7

Add the flour and salt mixture and stir with a large spatula or wooden spoon until barely combined. Stop when a few streaks of flour remain. Do not overmix.

Step 8

Gently fold in chocolate chips.

Step 9

Transfer the dough into the prepared pan and top with more chocolate chips if desired.

Step 10

Bake on the center rack of the oven for about 25 minutes or until edges are golden brown and center is set. Do not overbake.

Step 11

Remove from oven and cool completely before cutting into squares.