These are just really good.
115g (4 oz) butter
1 c peanut butter (home brand)
1/2 c sugar
1/2 c brown sugar
1 egg
1 tsp vanilla essence
1 1/4 c flour
1/2 tsp baking soda
1/2 tsp baking powder
pinch salt
Mix thoroughly the butter, peanut butter, sugars, egg and essence. Blend in remaining ingredients.
Place tablespoon-sized balls of dough onto trays. Flatten with a fork dipped in flour.
Bake 180C 14-16 minutes or until lightly browned.