Preheat oven to 350ºF. Place baking cups in muffin pan.
In medium bowl, combine flour, baking soda and baking powder. In large bowl, beat butter, peanut butter and sugar with an electric mixer until light and fluffy. Add eggs, sour cream and vanilla; mix until well combined. Alternately add flour mixture and milk to bowl, beating until just combined. Pour batter into prepared pan..
Bake 16-18 minutes, or until toothpick inserted in center of cupcake comes out clean. Cool completely before glazing.