) Arrange a rack in the middle of the oven and heat to 350°F. Spread the bread slices in a single layer on a baking sheet. Toast until dry and very lightly golden-brown, about 10 minutes. Set aside to cool slightly.

) Coat a 3-quart or 9x13-inch baking dish with 1/2 tablespoon of the butter. Spread the remaining butter on one side of the bread slices. Cut or tear the buttered bread slices into roughly 1-inch pieces and place them in the prepared baking dish in an even layer.

) Whisk the eggnog, milk, eggs, sugar, bourbon (or vanilla, if using), and salt together in a large bowl. Pour evenly over the bread cubes and gently press down with your hands to make sure all of the bread gets saturated. Cover the dish with aluminum foil and refrigerate for 1 hour or overnight.

) To bake, arrange a rack in the middle of the oven and heat to 350°F.

) Uncover the casserole. Bake until a tester inserted in the center comes out clean and the tips of the bread are lightly toasted, 45 to 50 minutes in a metal pan or up to 55 minutes in a glass or ceramic pan. If the crust seems like it's getting dark before the casserole is done, tent the dish loosely with foil.

) Transfer the casserole to a wire rack and let stand at least 10 minutes before serving. Sprinkle with powdered sugar and cinnamon and serve with warm maple syrup!

A Borthwell family favorite on Christmas morning!!