2 cups sugar
1 (5 oz.) can evaporated milk
1/2 cup (1 stick) butter
1 (6 oz.) pkg. chocolate chips
1 tsp. vanilla
1/2 cup nuts (optional)

Boil sugar and milk for 6 minutes, stirring with wooden spoon.

Remove from heat and add remaining ingredients. Beat until butter and chocolate are melted and mixture begins to thicken.

Pour on buttered pan; refrigerate.