First Peanut-Butter Cookies

Preheat oven to 350 . Combine flour, baking soda, & baking powder. With an eletric mixer at medium-low speed, beat butter, & peanut butter, until smooth & creamy. Beat in sugars & vanilla. Beat in egg. Reduce speed to low & beat in flour mixture. Roll dough into 1" balls and put about 3"s apart on an ungreased baking sheet. Using a fork, dipped in water, press a criss-cross pattern to flatten each ball. bake until edges just start to brown, about 10 minutes.