Double Chocolate Fudge

This is my version of another recipe. It makes SO much - great for giving as gifts. I often cut the amount of nuts in half and only add them to half the mixture so I have with and without nuts.

1 tablespoon plus 1/2 cup butter, divided
2 3/4 c. milk chocolate chips
4 c. semisweet chocolate chips
1 jar marshmallow creme
1 can evaporated milk
4-1/2 c. sugar
2 c. chopped walnuts or pecans

Line a 13-in. x 9-in. pan with foil and butter the foil with 1 tablespoon butter; set aside. In a large heat-proof bowl, combine the chocolate chips and marshmallow creme; set aside. In a large saucepan over medium-low heat, combine the milk, sugar and remaining butter. Bring to a boil, stirring constantly. Boil and stir for 4-1/2 minutes. Pour over chocolate mixture; stir until chocolate is melted and mixture is smooth and creamy. Stir in walnuts. Pour into prepared pan. Cover and refrigerate until firm. Store in the refrigerator. Makes 6 pounds.