Double Chocolate Fudge

2 c (12 oz) semi-sweet chocolate chips
1 (11 1/2 oz) package milk chocolate chips
1 (14 oz) can sweetened condensed milk
2 TB cream or milk
2 ts vanilla extract
1 c chopped walnuts (optional)

In saucepan, over low heat, melt semi-sweet chocolate chips with 2/3 cup sweetened condensed milk, 1 TBSP cream and 1 tsp vanilla. Remove from heat; stir in 1/2 cup walnuts. Spread evenly into foil-lined 9-inch square pan. In another saucepan, over low heat, melt milk chocolate chips with remaining sweetened condensed milk, 1 TBSP cream and 1 tsp vanilla. Remove from heat; stir in remaining walnuts. Spread over fudge in pan. chill 2 hours or until firm. Turn fudge onto cutting board; peel off foil and cut into squares. Store loosely covered at room temperature. Makes about 2 1/2 pounds.