1/2 cup unsalted butter, room temperature
3/4 cup peanut butter
1/2 cup granulated sugar
1/2 cup brown sugar
1/2 teaspoon vanilla
1 cup all-purpose flour
3/4 teaspoon baking soda
6 ounces semisweet or bittersweet chocolate chunks
Preheat oven to 350°.
Cream butter, peanut butter, and sugars. Add egg and vanilla; mix well.
Sift flour and baking soda together. Add to butter mixture and beat until just combined. Fold in chocolate.
Form with 1 1/2-ounce scoop (about 3 tablespoons), place on parchment- or Silpat-lined cookie sheets, and flatten slightly.
Bake until golden, about 12 minutes.