Overnight Blueberry French Toast Casserole combines brioche or challah, blueberries, and a vanilla-cinnamon custard beneath a brown sugar streusel. Assemble it the evening before, refrigerate overnight, and bake it the following morning.
This recipe serves eight, making it a convenient centerpiece for a weekend breakfast, Christmas morning, or Mother’s Day brunch. Preparing the casserole ahead leaves you more time to set the table and enjoy breakfast with your guests.
For a savory dish to serve alongside it, try our Spinach and Feta Quiche.
Tips for Making Overnight Blueberry French Toast Casserole
Use slightly stale bread and cut it into evenly sized cubes. Gently press the bread into the custard so the upper pieces absorb some liquid too.
Distribute the blueberries throughout the dish rather than concentrating them in one area. If using frozen blueberries, add them without thawing.
Refrigerate the streusel separately and sprinkle it over the casserole just before baking. This keeps the topping from soaking in the custard overnight.
Check the center before removing the casserole from the oven. A browned topping does not necessarily mean the egg mixture underneath has finished cooking.
How to Check That Your French Toast Casserole Is Cooked
Use a food thermometer to check the center of the casserole. Egg dishes should reach an internal temperature of 160°F (71°C). If the topping browns before the center is ready, cover it loosely with foil and continue baking.
For more information, consult the FDA’s guidance on preparing and serving egg dishes safely.

Overnight Blueberry French Toast Casserole
Ingredients
Equipment
Method
- Grease a 9×13-inch baking dish with the tablespoon of butter.
- Arrange half of the bread cubes in the prepared baking dish. Sprinkle with 1 cup of blueberries, then add the remaining bread and blueberries.
- In a large bowl, whisk together the eggs, milk, heavy cream, maple syrup, brown sugar, vanilla, cinnamon, nutmeg, salt, and lemon zest.
- Slowly pour the custard mixture over the bread. Gently press the bread down with a spatula so it absorbs the liquid.
- Cover the baking dish tightly and refrigerate for at least 8 hours or overnight.
- To prepare the streusel, combine the flour, brown sugar, cinnamon, and salt in a medium bowl. Cut in the cold butter with a fork until coarse crumbs form. Stir in the pecans if using.
- Cover the streusel and refrigerate it separately overnight.
- The following morning, remove the casserole from the refrigerator and let it stand at room temperature for 20–30 minutes.
- Preheat the oven to 350°F. Sprinkle the cold streusel evenly over the casserole.
- Cover the baking dish loosely with aluminum foil. Bake for 30 minutes.
- Remove the foil and continue baking for 20–25 minutes, until the top is golden and the center is set. A knife inserted near the center should come out without liquid custard.
- Allow the casserole to rest for 10 minutes before serving.
- Dust with powdered sugar and serve warm with maple syrup and fresh blueberries, if desired.
Notes
Storing and Reheating Blueberry French Toast Casserole
Refrigerate leftovers promptly in covered containers and use them within 3 days. Dividing the casserole into portions makes it easier to reheat only what you need.
Reheat leftovers to an internal temperature of 165°F (74°C). Add fresh serving toppings after reheating.
More Brunch Recipes to Try
Round out your brunch menu with our Smoked Salmon and Avocado Toast. Prepare a smaller serving alongside the casserole to offer guests both sweet and savory options.
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