Peanut Butter-Chocolate Chip Cookies
["1/2 c. butter softened", "1/2 c. creamy peanut butter", "1/2 c. granulated sugar", "1/2 c. packed light brown sugar", "2 eggs", "1 tsp. vanilla", "1 1/3 c. all-purpose flour", "1 tsp. baking soda", "1/4 tsp. salt", "1 3/4 c. semisweet chocolate pieces"]
["Preheat oven to 350\u00b0. Grease cookie sheet."]
["butter", "peanut butter", "sugar", "brown sugar", "eggs", "vanilla", "flour", "baking soda", "salt", "chocolate"]