These peanut butter cookies have been a favorite for years!
Heat oven to 375°F. Combine brown sugar, butter and peanut butter in large bowl. Beat on medium speed until well mixed. Add egg and vanilla; continue beating until well mixed. Reduce speed to low; add flour, baking powder, baking soda and salt. Beat until well mixed.
Shape dough into 1-inch balls; roll in sugar. Place 2 inches apart onto ungreased cookie sheets; flatten balls in criss-cross pattern with fork dipped in sugar. Bake for 8 to 10 minutes or until edges are lightly browned.