CRUMB MIXTURE:

1/2 c. firmly packed brown sugar
1/2 c. peanut butter
1/4 c. softened butter
1 c. flour

Preheat oven to 350 degrees. Prepare crumb mixture. In a small mixer bowl cream brown sugar, peanut butter and butter until light and fluffy. Add flour; blend until crumbly. Sprinkle into ungreased 8x8 pan. Bake for 10-15 minutes. Set aside 1/2 of crumbs (1 cup). Lightly press remaining crumbs into pan.

FILLING:

1 (8 oz.) pkg. Philadelphia cream cheese
1/2 c. sugar
1/4 c. peanut butter
1 tsp. vanilla
2 eggs
2 c. thawed Cool Whip
1 (6 oz.) pkg. semi-sweet chocolate chips

In a small bowl combine first 4 ingredients. Beat at medium speed until creamy. Add eggs one at a time, beating well after each. Fold in cream topping. Pour over crumbs in pan. Melt chocolate; drizzle over. Gently cut through to marbelize. Sprinkle with reserved crumbs. Freeze 2 hours. Remove 15 minutes before serving. Yield: 12-15 servings.