Adapted from themotherhuddle.com
cup crunchy style peanut butter
cup butter (softened)
cup firmly packed brown sugar
cup granulated sugar
teaspoon backing powder
cup semi-sweet chocolate chips
Preheat oven to 350 degrees Beat together peanut butter, butter, brown sugar, and sugar until creamy. Beat in eggs, and vanilla. In a separate bowl, combine flour, baking powder and salt. Blend dry ingredients into peanut butter mixture. Spread into a 9 X 13 inch greased baking pan. Sprinkle chocolate chips over surface. Place into oven and cook for 5 minutes. Remove and marbleize. Return to oven and cook for another 30 minutes. Cool and then cut into bars.