1 (12 oz.) pkg. peanut butter flavored chips
1 (14 oz.) can sweetened condensed milk
1/4 c. butter
1/2 c. chopped peanuts (optional)
1 c. semi-sweet chocolate chips

In heavy saucepan, over low heat, melt peanut butter chips, 1 cup sweetened condensed milk and 2 tablespoons butter; stir occasionally. Remove from heat; stir in peanuts. Spread mixture into wax paper-lined 8-inch square pan.

In small saucepan, melt chocolate chips, remaining milk and butter. Spread chocolate mixture on top of peanut butter mixture. Chill 2 hours or until firm. Turn fudge onto cutting board; peel off paper and cut into squares. Store loosely covered at room temperature. Makes about 2 pounds.