modified from MSL February 2004
makes one 8 x 8-inch pan
3 oz unsalted butter
6 oz chocolate (semi-sweet and bittersweet blend)
.25 C non-dutched cocoa powder
.5 C flour
.25 t baking powder
1 C sugar
2 large eggs
2 t vanilla extract
.25 t salt
Preheat oven to 350ºF.
Butter a 8 x 8-inch square glass baking dish. Line dish with parchment paper, leaving a 1-inch overhang on two sides; butter lining, excluding overhang.
Sift together flour and baking powder, set aside.
Combine butter, chocolate and cocoa powder in a medium microwave-safe bowl. Microwave 1-2 minutes on medium power, stirring every 30 seconds. Once most of the chocolate is melted, remove from microwave and stir until all pieces are dissolved. Set aside to cool slightly.
In a large bowl, whip together sugar, eggs, vanilla and salt until the mixture is pale and light in texture. Add chocolate mixture and beat just to combine. Sift in flour mixture and beat just to combine. Scrape down bowl and stir with a spatula to homogenize the mixture.
Pour into prepared pan and smooth top. Bake for 30-35 minutes, until a knife inserted halfway between side and center comes out almost clean. Cool in pan 15 minutes before removing to wire rack to cool completely. Slice after fully cooled.
For optimal flavor, store brownies in an airtight container overnight before serving.