Heat oven to 350°F (325°F for dark or nonstick cookie sheets). In large bowl, beat cake mix, peanut butter, brown sugar, butter and eggs with electric mixer on medium speed until well blended. Stir in chocolate chips.
On ungreased cookie sheets, drop dough by rounded tablespoonfuls 2 inches apart. Flatten dough slightly with fingers.
Bake 9 to 11 minutes or until edges are set (centers will be soft). Cool 1 minute; remove from cookie sheets to cooling racks. Store covered.