1 1/2 cups chunky peanut butter, divided

8 tablespoons (1 cube) butter, room temperature

1 cup brown sugar

1/2 cup granulated sugar

1 teaspoon vanilla extract

3 eggs

1 cup all purpose flour

1/2 teaspoon salt

3 cups chocolate chips, divided

1. Preheat oven to 350 degrees. Grease a 9 by 13 inch pan, or spray liberally with nonstick cooking spray; set aside.

2. Beat together 1 cup peanut butter, butter, brown and granulated sugars and vanilla. Scrape down sides of bowl. Beat in the eggs. Then add flour and salt; beating to blend. Stir in 1 cup chocolate chips.

3. Transfer batter to prepared pan and bake about 25 to 30 minutes, until edges begin to brown and it tests done in the center. Transfer to a rack. Immediately sprinkle top with 2 cups chocolate chips. When chips begin to melt spread chocolate. Spoon remaining 1/2 cup peanut butter over the top and swirl together. Cool well before cutting.