It's possible to substitute chocolate pieces for unsweetened cocoa powder; but you'll have to make some adjustments!
If you use 1 tablespoon unsweetened cocoa powder plus 2 teaspoons sugar and 2 teaspoons shortening, it is equivalent to 1 ounce semisweet chocolate. Or, 3 tablespoons cocoa powder plus 1 tablespoon oil or shortening is equivalent to 1 ounce unsweetened chocolate.
It may be easier to use unsweetened chocolate in place of the cocoa, leaving out some of the oil; this reduces the need to adjust sugar.
Prep: 20 minutes Cool: 15 minutes Bake: 30 minutes Oven: 350 degrees F
Makes: 16 brownies
1/2 cup butter
3 ounces unsweetened chocolate, coarsely chopped
1 cup sugar
1 teaspoon vanilla
2/3 cup all-purpose flour
1/4 teaspoon baking soda
1/2 cup chopped nuts (optional)
1 recipe Chocolate-Cream Cheese Frosting (optional)
1. In a medium saucepan heat and stir butter and unsweetened chocolate over low heat until smooth; set aside to cool. Preheat oven to 350 degrees F. Line an 8x8x2-inch baking pan with foil, leaving about 1 inch of the foil extending over the ends of pan. Grease foil; set pan aside.
2. Stir the sugar into the cooled chocolate mixture. Add the eggs, 1 at a time, beating with a wooden spoon just until combined. Stir in vanilla. In a small bowl stir together the flour and baking soda. Add flour mixture to chocolate mixture; stir just until combined. If desired, stir in nuts. Spread the batter evenly in the prepared pan.
3. Bake in the preheated oven for 30 minutes. Cool in pan on a wire rack. If desired, spread Chocolate-Cream Cheese Frosting over cooled brownies. Remove brownies from pan, using the overlapping foil to lift brownies. Place on cutting board; cut into brownies.