Melt the chocolate chips on top, and then swirl them through the peanut butter layer before it has finished baking. Easy, fairly quick, sure to please. I probably picked this recipe up here on TRL, and I've made it lots of times since!

PEANUT BUTTER SWIRL BARS

1/2 cup peanut butter
1/3 cup margarine, softened
3/4 cup firmly packed brown sugar
3/4 cup granulated sugar
2 eggs
2 tsp. vanilla
1 cup flour
1 tsp. baking powder
1/4 tsp. salt
1 (6 oz.) pkg. chocolate chips

Preheat oven to 350 degrees F. Grease a 9x13x2 inch baking pan.

Cream together peanut butter and margarine; gradually. Add sugars, beating well at medium speed of an electric mixer. Add eggs and vanilla and beat well.

Combine flour, baking powder, and salt in a small bowl; stir well. Add flour mixture to creamed mixture, mixing well. Spread batter in prepared pan.

Bake at 350 degrees F for 5 minutes.

Remove from oven and sprinkle with chocolate chips. Return to oven till chips are melted, about 4 minutes.

Swirl through batter with a knife. Return to oven and bake 20 minutes or until edges start to pull away from the pan. Let cool; cut into bars while still slightly warm.