Name: Overnight French Toast Casserole
Prep time: 15 min
Cook time: 50 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 1 loaf bread, preferably brioche or challah (day old is best; stale works great); 6 large eggs; 2 cups milk (whole milk for creaminess; swap for plant milk in a pinch); 1 cup heavy cream (can use additional milk for a lighter version); 1/2 cup brown sugar; 1 teaspoon vanilla extract; 1 teaspoon ground cinnamon; 1/4 teaspoon salt; 1 cup mixed berries (blueberries, strawberries, raspberries), for serving; Crumble topping:; 1/2 cup brown sugar; 1/4 cup all purpose flour; 1/4 cup butter, cold and cubed; 1 teaspoon ground cinnamon

Overnight French Toast Casserole

By:

Patricia Hayes

| Published on:

February 8, 2026

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I first made this overnight French toast casserole on a sleepy holiday morning and it instantly became the dish everyone asked for again. It is custardy, slightly sweet, and forgiving enough to prep the night before. Using brioche or challah gives a rich texture that soaks up the egg mixture without turning mushy. If you want an even sweeter, more cinnamon-forward twist for another morning, try the cinnamon roll French toast bake for a different take on the same cozy idea.

Why you’ll love this dish

This casserole turns a handful of pantry staples into a showstopper breakfast or brunch with almost no morning work. It is ideal when you need something that feeds a crowd, lets you sleep in, and still looks and tastes homemade. The overnight soak means the bread soaks through, producing a soft interior and a crisp, buttery top once baked.

"Made this for a weekend brunch and everyone went back for seconds. The crumble is the perfect sweet crunch."

The cooking process explained

Step back and breathe: you cube the bread, whisk a simple custard, layer and soak overnight, then top with a buttery crumble and bake until golden. The process is straightforward and split across two sessions so you can do the prep the night before and bake in the morning. Expect about 15 minutes hands on the first night, then 10 minutes prep plus 45 to 50 minutes baking the next day.

What you’ll need

1 loaf bread, preferably brioche or challah (day old is best; stale works great)
6 large eggs
2 cups milk (whole milk for creaminess; swap for plant milk in a pinch)
1 cup heavy cream (can use additional milk for a lighter version)
1/2 cup brown sugar
1 teaspoon vanilla extract
1 teaspoon ground cinnamon
1/4 teaspoon salt
1 cup mixed berries (blueberries, strawberries, raspberries), for serving
Crumble topping
1/2 cup brown sugar
1/4 cup all purpose flour
1/4 cup butter, cold and cubed
1 teaspoon ground cinnamon

Ingredient notes: day old brioche soaks nicely without falling apart. If you prefer less richness, use 1 cup heavy cream and 1 cup milk instead of the full cup of cream. For gluten free, use a sturdy gluten free loaf and a GF flour for the crumble.

Directions to follow

Grease a 9 by 13 inch baking dish with butter or nonstick spray.
Cut the loaf into roughly 1 to 1.5 inch cubes. Place half the cubes evenly in the bottom of the dish.
In a large bowl, whisk eggs until combined. Add milk, heavy cream, 1/2 cup brown sugar, vanilla, 1 teaspoon cinnamon, and salt. Whisk until smooth.
Pour half of the custard mixture over the bread in the dish, pressing gently so the bread soaks some liquid.
Add the remaining bread cubes on top, then pour the remaining custard over everything. Press lightly so the custard soaks in.
Cover tightly with plastic wrap and refrigerate overnight, or at least 6 hours. This step ensures even soaking.
When ready to bake, preheat oven to 350°F (175°C).
Make the crumble by combining 1/2 cup brown sugar, 1/4 cup flour, 1 teaspoon cinnamon, and the cold cubed butter. Use a pastry cutter or your fingers to rub until the mixture forms coarse crumbs.
Sprinkle the crumble evenly over the soaked casserole.
Bake for 45 to 50 minutes, until the top is golden and the center is set (a knife inserted should come out mostly clean).
Let the casserole sit 5 minutes, then serve warm topped with mixed berries.

Best ways to enjoy it

Serve squares of the casserole on a warm plate with a spoonful of fresh mixed berries on top. Powdered sugar or a drizzle of maple syrup pair nicely if you want extra sweetness. For a brunch spread, offer a simple green salad, yogurt parfaits, or a plate of fresh fruit to balance the richness. If you like bite sized options for a party, the same flavors work well in smaller portions similar to the cinnamon roll French toast bites concept.

How to store & freeze

Cool completely before storing. Refrigerate leftovers in an airtight container for up to 4 days. To reheat, warm individual portions in a 350°F oven for 10 to 15 minutes or microwave for 45 to 90 seconds until heated through. To freeze, cut into portions, wrap tightly in plastic wrap and foil, and freeze up to 2 months. Thaw overnight in the refrigerator and reheat in the oven until hot. As with any egg based dish, keep it refrigerated and discard after 4 days for safety.

Helpful cooking tips

Use day old bread so the cubes absorb the custard without becoming soggy.
Let the custard rest for at least 6 hours. Longer soak time gives a more uniform custardy texture.
Cold butter for the crumble creates a crisp topping rather than a melted paste.
If the top browns too quickly, tent loosely with foil for the remaining bake time.
For even baking, avoid overfilling the dish; loosely packed cubes allow custard circulation.

Recipe variations

Nutty twist: sprinkle chopped pecans or sliced almonds into the crumble for texture.
Citrus brightening: add a teaspoon of orange zest to the custard for a fresh note.
Chocolate lovers: fold 1/2 cup mini chocolate chips into the custard before soaking.
Lower dairy: swap heavy cream for extra milk, or use a plant based cream alternative.
Savory adaptation: leave out the brown sugar and serve with browned butter and maple free toppings for a less sweet version.

Your questions answered

How long should I soak the bread?

Soaking overnight, about 8 hours, gives the best custard consistency. If short on time, allow at least 6 hours. Less than 4 hours risks dry pockets.

Can I use a different type of bread?

Yes. Brioche or challah are ideal for richness, but a sturdy French loaf or sourdough will work. Avoid very soft sandwich bread as it can become mushy.

Is it safe to leave the casserole overnight in the fridge?

Yes. Refrigerating the assembled casserole is safe and recommended. Make sure it is covered and kept at refrigerator temperatures below 40°F.

Can I make this dairy free or vegan?

For dairy free, use a full fat plant milk and a plant based cream substitute, and vegan butter for the crumble. For a fully vegan version, replace eggs with a commercial egg replacer designed for baking and expect a slightly different texture.

How do I know when it is done baking?

The edges should be golden and the center mostly set. A knife inserted in the middle should come out with only a few moist crumbs, not runny custard.