Brown Butter Brownies with Walnuts

20 tablespoons unsalted butter, in chunks (it's faster with room temperature butter)

2 1/2 cups sugar

1 1/2 cup natural unsweetened cocoa powder (spooned into cup to measure, then leveled)

4 teaspoons water

2 teaspoons vanilla extract

1/2 teaspoon salt

4 large eggs, chilled

2/3 cup plus 2 tablespoons unbleached all purpose flour

2 cups walnut pieces

Position rack in bottom third of oven; preheat to 325°F. Lightly spray a 13x9" metal baking pan with cooking spray then line with parchment paper, leaving an overhang if possible. Melt butter in a deep medium saucepan over medium heat. Continue cooking, stirring constantly with a heatproof spatula until butter stops foaming, browned bits form at bottom of pan, and butter smells nutty, about 8 minutes. Remove pan from the heat; immediately add the sugar, cocoa, 4 teaspoons water, the vanilla, and salt. Stir with your spatula to blend. Let cool 5 minutes (mixture will still be hot). Add eggs to hot mixture 1 at a time, beating vigorously to blend after each addition. When mixture looks thick and shiny, add flour and stir until blended. Beat vigorously 60 strokes. Stir in nuts. Transfer batter to prepared pan.

Bake brownies until a toothpick inserted into center comes out almost clean (with a few moist crumbs attached), about 25 minutes. Cool in the pan on a rack. Using the parchment sling handle, lift brownies from pan and cut as desired.

Adapted from Bon Appetit, February 2011