1 (12 oz.) pkg. peanut butter chips
1 (14 oz.) can sweetened condensed milk (not evaporated)
1/4 c. butter
1/2 c. chopped peanuts (optional)
1 c. (6 oz.) semi-sweet chocolate chips

In large saucepan, melt the peanut butter chips with one cup of milk and two tablespoons butter, stirring constantly. Remove from heat and spread into a wax paper-lined pan, 8-inch square.

In small saucepan, melt chocolate chips, remaining butter and remaining milk. Spread this over the peanut butter mixture. Chill 2 hours. Turn fudge onto cutting board. Peel off wax paper and cut into squares.