Mix packet of Cranberry and Walnut Dip Mix and hot water with fork. Let set for 15 minutes.
Preheat oven to 350°.
Grease a 13x9-inch baking pan. Evenly spread bread pieces in the pan.
In a bowl, mix together Cranberry and Walnut Dip Mix, white sugar, eggs, milk, and vanilla in a large bowl. Pour this mixture on top of bread pieces in pan and allow to soak.
Mix together brown sugar, butter and (optional) walnuts. Sprinkle over top.
Bake for 40 to 45 minutes, or until set. Remove from oven and serve with whipped topping, ice cream, or plain.