I still remember the first time I made this French toast casserole: warm, custardy bread with a crunchy oat crumble on top filled the kitchen with cinnamon-scented steam, and everyone hovered around the baking dish until the first square was cut. This make-ahead breakfast hits the sweet spot between casual and special-occasion cooking, perfect for a weekend brunch or a cozy holiday morning. If you want a cinnamon-swirled spin for a crowd, try Cinnamon Roll French Toast Bites.
Why you’ll love this dish
This casserole takes all the comforting parts of French toast and turns them into something you can pop in the oven and forget for a bit. It feeds a crowd without fuss, uses one loaf of bread, and the crumble topping gives a bakery-style finish without complicated techniques. It works for slow weekend mornings, overnight guests, or when you want to bring an easy-but-impressive dish to a brunch potluck.
"A crowd-pleaser every time: custardy interior, crunchy top, and simple enough to make the night before."
The recipe is forgiving. Use day-old challah or brioche for the best texture, or swap in another rich loaf if needed. The brown sugar-oat crumble adds texture and flavor, and you can add nuts for a toasty note.
Preparing French Toast Casserole
Step-by-step overview
- Cube a rich, slightly stale loaf and arrange it in a 9×13-inch dish.
- Whisk a simple custard of eggs, milk, sugar, vanilla, and spices.
- Pour custard over the bread and let it soak so the center turns custardy.
- Make a quick oat-and-brown-sugar crumble and scatter it on top.
- Bake until puffed, golden, and set; rest briefly, then serve warm.
These steps are straightforward, and the hands-on time is minimal. The soak time gives the bread a chance to absorb the custard so each bite is soft but not soggy.
What you’ll need
- 1 loaf of bread (preferably challah or brioche), cut into 1-inch cubes (about 10 to 12 cups)
- 4 large eggs
- 2 cups milk (whole milk gives the richest result; 2% works fine)
- 1/2 cup granulated sugar
- 1 teaspoon vanilla extract
- 1 teaspoon ground cinnamon
- 1/4 teaspoon ground nutmeg
- 1/4 cup chopped nuts (optional: pecans or walnuts)
For the crumble: - 1/2 cup brown sugar
- 1/2 cup oats (old-fashioned work best)
- 1/4 cup all-purpose flour
- 1/4 cup unsalted butter, cold and cut into small cubes
Substitution notes: If you do not have challah or brioche, use a sturdy white loaf or country bread. For dairy-free, swap in unsweetened almond milk and a vegan butter alternative for the crumble, though texture will be slightly different.
Step-by-step instructions
- Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking dish with butter or nonstick spray.
- Cut the loaf into 1-inch cubes and spread them evenly in the prepared dish.
- In a medium bowl, whisk together the eggs, milk, granulated sugar, vanilla extract, ground cinnamon, and ground nutmeg until smooth.
- Pour the custard evenly over the bread cubes. Press down lightly so more of the bread soaks up the mixture. Let the dish sit for 10 to 30 minutes to absorb.
- In another bowl, combine the brown sugar, oats, flour, and optional chopped nuts. Add the cold butter cubes and use your fingers or a pastry cutter to mix until the mixture is coarse and crumbly.
- Sprinkle the crumble evenly over the soaked bread.
- Bake for 30 to 40 minutes until the top is golden and the center is set. A knife inserted near the center should come out mostly clean with a few moist crumbs.
- Remove from the oven and let rest for 5 minutes. Serve warm.
How to serve French Toast Casserole
Best ways to enjoy it
Serve slices warm straight from the dish. Top with a dusting of powdered sugar, a drizzle of maple syrup, or a scoop of vanilla yogurt. Fresh berries or a warm fruit compote brighten the richness and add acidity. For a heartier plate, offer scrambled eggs and fresh fruit on the side. If you want a savory counterpart that still feels brunch-appropriate, check out this idea for Sausage French Toast Roll-Ups.
Presentation tips: cut neat squares with a sharp knife and use a spatula that supports the full piece when plating to keep the crumble intact.
Storage and reheating tips
Keeping leftovers fresh
- Refrigerator: Store cooled leftovers in an airtight container for up to 3 days.
- Reheat: Warm individual portions in a 325°F oven for 10 to 15 minutes or microwave for 45 to 60 seconds. To refresh the crumble, sprinkle a few extra oats or a small pat of butter before reheating.
- Freezing: Wrap cooled squares tightly in plastic wrap and foil, or place in a freezer-safe container for up to 2 months. Thaw overnight in the refrigerator before reheating.
Food safety note: Cool the casserole to room temperature no longer than two hours before refrigerating. When reheating, heat until steaming hot throughout.
Helpful cooking tips
- Use slightly stale bread: Day-old bread soaks better and prevents a gummy interior. If your loaf is fresh, dry the cubes on a baking sheet at 250°F for 10 minutes.
- Custard ratio: Four eggs to two cups of milk yields a nicely set custard. For a richer custard, substitute half-and-half for some of the milk.
- Pressing matters: Press the bread gently after pouring the custard so the center soaks but pieces keep their shape.
- Cold butter for crumble: Keep the butter cubed and cold so the crumble bakes into crisp, separate pieces rather than melting into greasy clumps.
- Check doneness by feel: The casserole should be puffed and spring back slightly in the center; if it jiggles like liquid, add a few more minutes.
Creative twists
- Berry-pecan: Fold 1 cup fresh or frozen berries into the bread before pouring the custard and use chopped pecans in the crumble.
- Maple-apple: Replace half the granulated sugar with maple syrup, and add thinly sliced apples to the top before baking.
- Nut-free: Omit nuts and increase oats slightly for a nut-free crumble.
- Savory version: Reduce sugar, skip the crumble, add shredded cheese and herbs, and fold cooked sausage or roasted vegetables into the cubes for a brunch casserole that leans savory.
Common questions
How long does it take to make this casserole?
Hands-on time is about 15 to 25 minutes. Include soak time and baking, and plan for 50 to 75 minutes total from start to finish.
Can I assemble this the night before?
Yes. Assemble the casserole, cover tightly, and refrigerate overnight. If you prefer a crisper top, wait to add the crumble until just before baking.
Can I use stale or fresh bread?
Stale or day-old challah or brioche is ideal because it soaks evenly without becoming mushy. If your loaf is fresh, cube it and dry the pieces in a low oven for 8 to 12 minutes before assembling.
How do I know when the casserole is done?
The top should be golden and the center set. Insert a knife into the middle; it should come out mostly clean with a few moist crumbs. If it still wiggles like liquid, return it to the oven for 5 to 10 more minutes.
Can I make this dairy-free or egg-free?
For dairy-free, substitute plant-based milk and a vegan butter for the crumble; texture will be slightly different. Egg-free versions need a custard substitute such as a commercial egg replacer or a blended mixture of silken tofu and non-dairy milk, but results will vary.
Is it safe to leave the custard-soaked bread overnight?
Yes, chilling the assembled casserole overnight in the refrigerator is safe. Do not leave it at room temperature for more than two hours before refrigerating.
French Toast Casserole
Ingredients
Method
- Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking dish with butter or nonstick spray.
- Cut the loaf into 1-inch cubes and spread them evenly in the prepared dish.
- In a medium bowl, whisk together the eggs, milk, granulated sugar, vanilla extract, ground cinnamon, and ground nutmeg until smooth.
- Pour the custard evenly over the bread cubes. Press down lightly so more of the bread soaks up the mixture. Let the dish sit for 10 to 30 minutes to absorb.
- In another bowl, combine the brown sugar, oats, flour, and optional chopped nuts. Add the cold butter cubes and use your fingers or a pastry cutter to mix until the mixture is coarse and crumbly.
- Sprinkle the crumble evenly over the soaked bread.
- Bake for 30 to 40 minutes until the top is golden and the center is set. A knife inserted near the center should come out mostly clean with a few moist crumbs.
- Remove from the oven and let rest for 5 minutes. Serve warm.
