1. Preheat oven to 350 degrees F.  Grease 8-inch square or round cake pan.

2. Combine flour, baking powder and salt in a small bowl.  Set aside.

3. On the stove top, under low heat, melt peanut butter and butter together in a small saucepan, stirring frequently.  Remove from stove and stir in sugar.  Cool to tepid.

4. Add in egg and vanilla extract and stir until combined.

5.  By hand, blend in flour mixture in 2 additions.  Scrape batter into pan and smooth.

6.  Bake for 25 to 30 minutes.  Check bars at 20 minutes. They are done when a small amount of batter sticks to the toothpick when inserted in the center.  Do not overbake. When done, let cool in the pan on a wire cake.

NOTE:  These can be dropped on greased cookie sheets and baked as peanut butter cookies.