1. 3/4 c. butter
2. 1 (12 oz.) pkg. semi-sweet chocolate chips
3. 12 tbsp. cocoa
4. 2 c. sugar
5. 4 eggs
6. 1/4 tsp. salt
7. 1 c. flour
8. 2 tsp. vanilla
9. 1 full cup chunky peanut butter

Mix first 3 ingredients in a saucepan large enough to use as a mixing bowl. Stir over low heat until fully mixed and melted. Remove from heat and stir in all other ingredients, except the peanut butter. Mix well and spread in a greased 9 x 13 inch pan. Drop large spoonfuls of peanut butter on top of brownie mixture and swirl with a knife for marble effect. Bake at 300 degrees for 35-40 minutes. Cool and cut into squares.