Overnight French Toast Casserole With an Eight-Hour Soak

• An eight-hour rest gives the bread time to absorb custard throughout, rather than leaving dry pockets under a wet top.
• Day-old French bread holds its shape better than soft sandwich bread, which keeps individual squares easier to lift and serve.
• A small amount of brown sugar stays on the surface, where it forms a cinnamon crust instead of dissolving completely into the custard.
• The recipe uses one baking dish from assembly through serving, making portions simple for a household schedule with staggered breakfasts.

• 1 loaf day-old French bread, cut into 1-inch cubes (680 g)
• 6 large eggs (300 g)
• 2 cups whole milk (480 g)
• 1 cup half-and-half (240 g)
• 1/2 cup granulated sugar (100 g)
• 2 teaspoons vanilla extract (8 g)
• 1 1/2 teaspoons ground cinnamon (4 g)
• 1/2 teaspoon kosher salt (3 g)
• 1/3 cup packed brown sugar (70 g)
• 2 tablespoons cold unsalted butter, diced (28 g)

Ingredient notes

• French bread is the workhorse here. Choose a day-old loaf with a firm crust and open crumb, then cut generous cubes; very fresh bread can compress as it soaks. Challah works too, but use slightly less custard if its slices are especially soft.
• Whole milk and half-and-half create a custard that is rich without becoming heavy. Use all whole milk for a lighter pan, but skip skim milk because the baked texture can turn thin and less creamy around the bread.
• Six large eggs set the soaked cubes into sliceable portions. Whisk until no streaks of white remain, especially around the bowl edge, so the custard bakes evenly across the dish.
• Brown sugar belongs mostly on top, where it creates a darker, lightly crackled finish. Dark or light brown sugar both work; dark brings a little more molasses flavor without changing the method.
• Vanilla, cinnamon, and salt keep the custard from tasting flat. Use pure vanilla extract when available, and grate a little nutmeg over the finished dish only if you want a warmer spice note.

1. 1Dry the bread

   Cut the French bread into 1-inch cubes and spread them on a sheet pan while you prepare the custard. If the loaf is very fresh, leave the cubes uncovered for 20 minutes. They do not need to become hard; a slightly dried exterior simply gives the custard more structure to cling to.

2. 2Butter the dish

   Butter a 9-by-13-inch baking dish thoroughly, including the corners. Add the bread cubes and arrange them in an even layer, but do not press them down. A few raised pieces are useful because they become the crisp, bronzed top after baking.

   

3. 3Whisk the custard

   In a large bowl, whisk eggs until smooth. Add whole milk, half-and-half, granulated sugar, vanilla, cinnamon, and salt, then whisk again until the sugar looks mostly dissolved. Pour slowly over the bread, aiming around the edges and across the center instead of flooding one spot.

4. 4Settle and cover

   Use the back of a spoon to nudge any completely dry cubes into the custard. Leave the highest pieces exposed. Cover the dish tightly and refrigerate for eight hours. This rest is what gives the casserole a cohesive center, so do not shorten it to a quick countertop pause.

5. 5Top before baking

   Heat the oven to 350°F. Remove the dish from the refrigerator while the oven heats, uncover it, and scatter brown sugar evenly across the surface. Dot with cold butter. The butter melts into the sugar and helps brown the top without requiring a separate topping mixture.

   

6. 6Bake until set

   Bake uncovered for 45 to 50 minutes, until the center is set, the edges are puffed, and a thermometer in the middle reads 160°F. Rest the pan for 10 minutes before cutting. That brief pause lets the custard settle, so squares hold together instead of slumping onto the spatula.

• Keep bread cubes close to 1 inch. Smaller pieces can turn overly soft during the long soak, while larger chunks may leave dry centers.
• Pour custard in stages if the bread rises above the dish rim. Pause for one minute between pours so liquid can work down through the gaps.
• Do not stir the soaked bread before baking. The untouched top layer is what provides those browned, crisp edges.
• Bake on the middle rack. A lower rack can overdarken the base before the center has set.
• If the top browns early, loosely lay foil over the dish for the final 10 minutes, then check the center temperature.
• Let the casserole rest before slicing. Ten minutes makes cleaner squares and keeps syrup from pooling immediately.

Cut the casserole into squares and put warm maple syrup on the table rather than soaking the whole pan. Fresh berries, sliced bananas, or orange segments add a cold contrast to the cinnamon top. For a fuller brunch plate, pair it with crisp bacon or breakfast sausage and plain Greek yogurt. On a weekday, one square with fruit is enough to keep the dish from needing extra utensils or a formal sit-down spread.