This recipe is based one one from The Farm in Beverly Hills, but I have modified the technique somewhat and added vanilla. I also like to mix the cocoa powder in with the melted chocolate rather than sift it in at the end with the cake flour.
1cupplus 2 tablespoons unsweetened cocoa powdernatural type
6largeeggs
3cupsgranulated sugar590 grams
½teaspoonsalt
2teaspoonsof vanillamy addition
1 ¼cupscake flour140 grams, sift after measuring**
Instructions
Preheat oven to 350 degrees. Line a 9x13 inch metal pan with nonstick foil.
In the top of a double boiler or in a large saucepan, melt butter with chocolate. Remove from heat and stir in the cocoa powder. Transfer mixture to a large mixing bowl.
Add the sugar to the hot chocolate mixture and stir until it is fully blended, then whisk in the eggs 1 at a time.
Stir in the salt and the vanilla, then sift in the flour and stir until blended.
Pour batter into pan and bake until top is firm and a tester inserted into center comes out with crumbs, 40-45 minutes.
Let cool completely, then cover and chill overnight. These are better on Day 2.
Notes
Cake flour can be lumpy, so I recommend sifting it after you measure it and then sifting it again into the brownie batter.