Preheat oven to 350. Line baking sheets with parchment paper. Whisk flours, soda and salt in a small bowl. With electric mixer on medium speed, beat butter and peanut butter in large bowl until creamy. Add sugar, egg and vanilla until light and fluffy. On low speed add flour mixture, beating till just blended. Roll into balls and flatten with fork and place on pans. Bake until browned on bottom12-15 minutes. Let cool for about one minutes on pan, transfer to rack and let cool completely.