PREHEAT oven to 350°F Combine flour, baking powder, baking soda and salt; set aside. Beat peanut butter, butter and sugars in large bowl with electric mixer on medium speed until light and fluffy. Add eggs and vanilla; mix well. Gradually add flour mixture, beating until well blended after each addition.
DROP tablespoonfuls of dough, 2 inches apart, onto greased baking sheets. Flatten each, in criss-cross pattern, with tines of fork.
BAKE 8 to 10 minute or until golden brown. Cool 5 minute Remove from baking sheets to wire racks; cool completely.