Combine Milnot and sugar in heavy 4-quart saucepan.
Add marshmallows and butter and cook over low heat until melted. Heat may be turned to medium.
Bring mixture to full boil and stir 4 minutes.
Remove from heat; stir in chocolate chips until melted.
Blend vanilla and nuts.
Pour into lightly buttered 9x13x2 inch pan. Allow to cool. Candy may be refrigerated or frozen once it is firm. Makes 5 pounds.