Overnight Cranberry Orange French Toast Casserole

Name: Overnight Cranberry Orange French Toast Casserole
Ingredients: FRENCH TOAST CASSEROLE; 1 13 ounce loaf Italian bread; 6 large eggs; 1 tablespoon light brown sugar; 2 3/4 cups whole milk; 1 1/2 teaspoons vanilla; 2 teaspoons fresh orange zest; 1 pinch salt; 1/4 teaspoon cinnamon; 3/4 cup fresh cranberries; BROWN SUGAR TOPPING; 8 tablespoons unsalted butter, softened; 1 1/2 cups light brown sugar; 1 cup chopped walnuts