Cream together butter, peanut butter and sugar. Beat in eggs.

In a seperate bowl, sift together flour, baking powder, baking soda and salt. Stir in batter. Put batter in refrigerator for 1 hour.

Roll into 1 inch balls and put on baking sheets. Flatten eaxh ball with fork, making a criss - cross pattern. Bake in preheated 375°F oven for about 10 minutes or until cookies brown. Do not over bake.