Martha's favorite brownie recipe eschews the more traditional nuts in favor of a generous amount of chocolate chunks.
- 1 cup (2 sticks) unsalted butter, room temperature, plus more for dish and parchment
- 1 2/3 cups sifted all-purpose flour, plus more for parchment
- 8 ounces unsweetened chocolate, chopped
- 5 large eggs
- 2 teaspoons pure vanilla extract
- 3 1/4 cups sugar
- 1/4 teaspoon salt
- 7 ounces ounces semisweet chocolate, cut into chunks (1 1/4 cups)
Heat oven to 425 degrees. Butter a 9-by-13-inch glass baking dish, and line dish with parchment paper. Butter and flour parchment. Set dish aside.
Place unsweetened chocolate and butter in the upper pot of a double boiler; melt over barely simmering water, stirring occasionally. Remove from heat, and set aside.
In the bowl of an electric mixer fitted with the whisk attachment, combine eggs, vanilla, and sugar; beat on high speed for 10 minutes. Reduce speed to low; add chocolate mixture, beating to combine. Add flour and salt gradually, beating just to combine. Fold in semisweet chocolate chunks.
Pour batter into the prepared baking dish. Bake bars until edges just start to pull away from pan, but the center is still moist, 25 to 30 minutes. Transfer dish to a wire rack to cool. Using a serrated knife, cut bars into 24 pieces. Store brownies in an airtight container for up to 1 week.