After an extensive side-by-side comparison, this classic brownie was the unanimous favorite brownie for our family. From Smitten Kitchen, Adapted from Cook’s Illustrated. Be sure to test for doneness before removing the brownies from the oven. If underbaked (the toothpick has batter clinging to it) the texture of the brownies will be dense and gummy. If overbaked (the toothpick comes out completely clean), the brownies will be dry and cakey. (Note: this recipe from Smitten Kitchen is amazing and a bit simpler or even try it in mini brownie bites).
1 cup (4 ounces) pecans or walnuts, chopped medium (optional)
1 1/4 cups (5 ounces) cake flour
1/2 teaspoon salt
3/4 teaspoon baking powder
6 ounces unsweetened chocolate, chopped fine
(1 1/2 sticks) unsalted butter, cut into six 1-inch pieces
2 1/4 cups (15 3/4 ounces) sugar
4 large eggs
1 tablespoon vanilla extract
Adjust oven rack to middle position; heat oven to 325 degrees. Line a 9x13 baking dish carefully with aluminum foil, pushing it into corners and up sides of pan; allow excess to overhand pan edges. Spray foil-lined pan with nonstick cooking spray.
If using nuts, spread nuts evenly on rimmed baking sheet and toast in oven until fragrant, 5 to 8 minutes. Set aside to cool.
Whisk to combine flour, salt, and baking powder in medium bowl; set aside.
Melt chocolate and butter in large heatproof bowl set over saucepan of almost-simmering water, stirring occasionally, until smooth. (Alternatively, in microwave, heat butter and chocolate in large microwave-safe bowl on high for 1 minute, then stir and heat for 30 seconds more. Stir again, and, if necessary, repeat in 15-second increments; do not let chocolate burn.)
When chocolate mixture is completely smooth, remove bowl from saucepan and gradually whisk in sugar. Add eggs on at a time, whisking after each addition until thoroughly combined. Whisk in vanilla.
Add flour mixture in three additions, folding with rubber spatula until batter is completely smooth and homogeneous.
Transfer batter to prepared pan; using spatula, spread batter into corners of pan and smooth surface. Sprinkle toasted nuts (if using) evenly over batter.
Bake until toothpick or wooden skewer inserted into center of brownies comes out with few moist crumbs attached, 30 to 35 minutes. Cool on wire rack to room temperature, about 2 hours, then remove brownies from pan by lifting foil overhang. Cut brownies into 2-inch squares and serve. (Store leftovers in airtight container at room temperature, for up to 3 days, or in the freezer).