Peanut Butter Oatmeal Chocolate Chunk Cookies

1 cup flour
1 cup old-fashioned or quick-cooking oats
1/2 tsp. baking soda
1/2 tsp. CALUMET Baking Powder
1/4 tsp. salt
1/2 cup (1 stick) butter, softened
1/2 cup granulated sugar
1/2 cup firmly packed brown sugar
1/2 cup peanut butter
1 egg
1-1/2 tsp. vanilla
6 squares BAKER'S Semi-Sweet Baking Chocolate, coarsely chopped

PREHEAT oven to 375°F. Mix flour, oats, baking soda, baking powder and salt; set aside. Beat butter, sugars and peanut butter in large bowl with electric mixer on medium speed until light and fluffy. Add egg and vanilla; mix well. Gradually add flour mixture, mixing until well blended after each addition. Stir in chocolate.
DROP heaping tablespoonfuls of dough, 2 inches apart, onto ungreased baking sheets.
BAKE 10 to 12 min. or until lightly browned. Cool 1 min.; remove from baking sheets to wire racks. Cool completely.