How to Bake a French Toast Casserole Things You'll Need 1/3 cup unsalted butter, 3/4 cup + 1/2 cup light brown sugar 6 eggs 1 cup milk 1 cup heavy cream 1 teaspoon vanilla extract 1 teaspoon brandy, Kahlua or rum (optional) 1 teaspoon cinnamon 1 teaspoon nutmeg 1 loaf of bread, such as brioche, challah, sourdough, white or raisin bread - cut into 1/2 inch / 1.5 centimeter slices 1/2 cup walnuts, or other additions of choice Step 1: Prepare Your Ingredients Begin by preparing your ingredients and buttering a 9 x 13 inch / 22 x 33 centimeter baking dish. Set the dish aside. Step 2: Melt the Butter and Sugar In a medium sized saucepan, melt together the butter and 3/4 of the brown sugar until dissolved over medium heat. Spread the mixture into the bottom of the prepared baking dish. Step 3: Whisk the Liquid Ingredients In a large bowl, whisk together the eggs, milk, cream, vanilla and liqueur, if using. Set aside. Step 4: Make the Sugared Topping In a small bowl, combine the remaining brown sugar, cinnamon and nutmeg. Set aside. Step 5: Layer in the Bread In your prepared baking dish, line a layer of your desired French toast bread. Step 6: Add the Liquid Ingredients Pour over the egg mixture. Step 7: Add in Extras (If Using) Sprinkle with the nuts followed by the brown sugar mixture then let stand to absorb for 1 hour or cover with plastic wrap and refrigerate overnight. Step 8: Bake When you are ready to bake, uncover and preheat the oven to 350 Fahrenheit / 170 Celsius and bake until puffed and golden, roughly 35 to 45 minutes. Step 9: Let Cool Let the casserole cool for 15 minutes before eating. It is best served warm and can be frozen in an air-tight container for up to a month.