1/3 c. butter
1/2 c. sugar
1/2 c. firmly packed brown sugar
2 eggs
1/2 c. smooth or crunchy peanut butter
1 c. flour (self-rising)
1/2 tsp. vanilla
1 (6 oz.) pkg. semi-sweet chocolate
1/2 c. chopped peanuts (optional)

Preheat oven to 350 degrees. Grease bottom of 9 inch square pan. Melt butter in large saucepan over low heat. Remove from heat; stir in remaining ingredients in order listed above. Mix with wooden spoon after each addition. Spread in prepared pan. Bake 30-35 minutes. Check with toothpick. Do not overbake; cool in pan. Cut into 16 squares.