Prep 10 mins
Cook 25 mins
- 2 1⁄2 cups all-purpose flour
- 1 1⁄2 teaspoons baking powder
- 1⁄2 teaspoon salt
- 1 3⁄4 cups packed light brown sugar
- 1 cup creamy peanut butter
- 1⁄2 cup margarine or 1⁄2 cup butter, slightly softened
- 3 large eggs
- 2 teaspoons vanilla extract
- 3 squares semisweet chocolate, melted
- 1 square unsweetened chocolate, melted
- 6 ounces semisweet chocolate pieces
- Preheat oven to 350 degrees F. In medium bowl, mix flour, baking powder, and salt.
- In large bowl, with mixer at medium speed, beat brown sugar, peanut butter, and margarine or butter until smooth, about 2 minutes. Reduce speed to low. Beat in eggs and vanilla; beat until smooth. Beat in flour mixture just until combined (dough will be stiff).
- Place one-third of dough (about 1 3/4 cups) in another large bowl. Stir in melted chocolate until blended; fold in 3/4 cup semisweet-chocolate pieces.
- Pat half of remaining peanut-butter dough into ungreased 13" by 9" metal baking pan. In random pattern, drop chocolate dough and remaining peanut-butter dough on top of peanut-butter layer; pat down with hand. Sprinkle with remaining chocolate pieces.
- Bake 25 to 30 minutes until toothpick inserted in center comes out clean. Cool in pan on rack.