Overnight French Toast Casserole
This overnight French toast casserole is the make-ahead breakfast that saves Christmas morning — or any slow weekend. Cubes of buttery brioche soak overnight in a cinnamon-vanilla custard, then bake into a golden, puffed casserole with crisp edges and a soft, custardy center, finished with a brown sugar crumble and warm maple syrup. You assemble it the night before in ten minutes, and in the morning it goes straight into the oven while you open presents.
The overnight soak is what makes it work. Dry-ish bread drinks up the custard without falling apart, and by morning every cube is flavored through. A loaf of day-old brioche or challah is ideal — soft white sandwich bread turns to mush, and fresh bread does not absorb the custard evenly. Serve it straight from the dish, family style, with maple syrup and a dusting of powdered sugar.
Prep time: 20 minutes (+ overnight chilling) Cook time: 45 minutes Servings: 8
What You’ll Need
- 9×13-inch baking dish
- Large mixing bowl
- Whisk
- Plastic wrap or foil
Baking it in a dish you can carry makes the morning easier — see our guide to the best insulated casserole carriers for potlucks for carriers that keep a 9×13 dish hot and level on the way to brunch.
Ingredients
- 1 loaf (about 16 oz) day-old brioche or challah, cut into 1-inch cubes
- 8 large eggs
- 2 cups whole milk
- 1/2 cup heavy cream
- 1/2 cup granulated sugar
- 2 teaspoons vanilla extract
- 1 1/2 teaspoons ground cinnamon
- 1/4 teaspoon ground nutmeg
- 1/4 teaspoon kosher salt
- 4 tablespoons unsalted butter, melted, for the topping
- 1/2 cup packed light brown sugar
- 1/2 cup all-purpose flour
- 1 teaspoon ground cinnamon
- Maple syrup and powdered sugar, for serving
Instructions
- Butter the dish. Grease a 9×13-inch baking dish with butter or cooking spray. Spread the bread cubes evenly in the dish.
- Whisk the custard. In a large bowl, whisk the eggs, milk, cream, granulated sugar, vanilla, cinnamon, nutmeg, and salt until smooth.
- Pour and soak. Pour the custard evenly over the bread cubes, pressing the bread down gently so every piece is moistened. Cover tightly with plastic wrap or foil.
- Chill overnight. Refrigerate for at least 8 hours, or overnight. The bread should be fully soaked and the custard mostly absorbed by morning.
- Heat the oven. In the morning, heat the oven to 350°F. Remove the dish from the fridge while the oven heats.
- Make the topping. In a small bowl, mix the melted butter, brown sugar, flour, and cinnamon with a fork until crumbly. Sprinkle the topping evenly over the casserole.
- Bake. Bake uncovered for 45 to 50 minutes, until the top is golden brown and the center is set — a knife inserted in the middle should come out mostly clean, with no liquid custard. If the top browns too fast, cover loosely with foil for the last 10 minutes.
- Rest and serve. Let the casserole rest for 10 minutes before serving so it sets and slices cleanly. Serve warm with maple syrup and a dusting of powdered sugar.
Tips for the Best Overnight French Toast Casserole
- Use day-old bread. Slightly stale brioche or challah absorbs the custard without falling apart — fresh bread turns soggy, and soft sandwich bread goes to mush. If your loaf is fresh, cube it and let it sit out for a few hours to dry.
- Do not skip the overnight soak. Eight hours is the minimum for the custard to soak all the way through. A short soak leaves dry cubes in the middle and a wet bottom.
- Make it your own. Fold in a cup of blueberries or diced apples before chilling, swap the cinnamon topping for chopped pecans, or serve it with a dollop of whipped cream for a holiday brunch.
Golden, custardy, and ready when you wake up — this overnight French toast casserole is the easiest impressive breakfast you will make all year.
