1/2 c. peanut butter
1/3 c. softened butter
3/4 c. brown sugar, packed
3/4 c. granulated sugar
2 eggs
2 tsp. vanilla
1 c. flour, sifted
1 tsp. baking powder
1/4 tsp. salt

Beat peanut butter, softened butter, brown sugar, and granulated sugar until creamy. Gradually beat in eggs and vanilla. Blend in flour, 1 teaspoon baking powder, 1/4 teaspoon salt. Spread in greased 13 x 9 x 2 inch pan. Sprinkle one (12 ounce) package chocolate chips over surface (2 cups).

Place in 350 degree oven for 5 minutes. Remove from oven, run knife through to marbelize. Return to oven for 20-25 minutes or until golden brown. Cool. Cut in bars.