- 1/2 cup all-purpose flour
- 1/2 cup unsweetened cocoa powder (not Dutch-process)
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1/2 cup unsalted butter, softened
- 3/4 cup packed dark brown sugar
- 1 large egg
- 1 cup semisweet chocolate chips
- 1 cup coarsely crushed peppermint hard candies
- Put oven rack in middle position and preheat oven to 375 degrees F. Line a 13- by 9-inch metal baking pan with 1 sheet of foil, allowing 2 inches of foil to hang over each end of pan, and butter foil (except overhang).
- Whisk together flour, cocoa powder, baking soda, and salt in a small bowl.
- Beat together butter and brown sugar in a large bowl with an electric mixer at high speed until pale and fluffy, about 3 minutes. Beat in egg until combined. Reduce speed to low, then mix in flour mixture until just combined. Stir in chocolate chips and candy.
- Spread dough evenly in pan and bake until puffed and beginning to pull away from sides of pan, about 20 minutes. Cool completely in pan on a rack, then, lifting with foil, transfer to a cutting board. Cut into bars and lift off foil with a spatula.