The best overnight french toast casserole recipe is easy to prepare in only 10 minutes! French bread is combined with a sweet vanilla egg & milk mixture and topped with a buttery streusel topping. This baked French toast casserole is made at night and baked in the morning so it's easy to prepare and enjoy.
Lightly grease a 9 x 13-inch baking dish, set aside.
Spread bread cubes evenly in the prepared baking dish.
In a large bowl, whisk together eggs, milk, half and half, brown sugar, granulated sugar, vanilla, cinnamon and sea salt.
Pour mixture over bread pieces in the prepared baking dish. Cover tightly with plastic wrap and store in the refrigerator for several hours or overnight.
Make the Streusel Topping
Add butter, brown sugar, flour, cinnamon and sea salt to a medium bowl. Use a fork, pastry cutter or your hands and cut in the ingredients to combine until the mixture resembles coarse crumbs.
Cover and store in the refrigerator overnight.
Assemble & Bake
When you’re ready to bake the French toast, preheat oven to 350 degrees F.
Remove the French toast bake and crumb topping mixture from the refrigerator and evenly sprinkle streusel over the top.
Bake for 40-50 minutes, or until the French toast is set and the top is lightly golden brown.
Whole Milk. You can use 2 % milk in place of whole milk, or you can use all half and half.
Half and half. You can replace half and half with whole milk or heavy cream.
Brown sugar. dark or light brown sugar can be used with excellent results.
Granulated sugar. You can replace the granulated sugar with brown sugar, if desired.
Salted butter. unsalted butter is a good substitute.
All-purpose flour. use unbleached, all-purpose flour for the best results.
StoreStore any leftovers in an airtight container in the refrigerator for 3-5 days and reheat in the microwave or oven on warm. FreezeFreeze the entire baked French toast casserole by letting it cool completely then covering it with plastic wrap and foil and putting it in the freezer for up to 1 month. Thaw it overnight in the refrigerator and then bake it loosely covered with foil according to the recipe instructions. Freeze this baked french toast in individual pieces by cutting the cooled casserole into individual servings. Then, place the pieces on a baking sheet and flash-freeze until hardened. Next, wrap the frozen pieces in plastic wrap and store in a freezer-friendly, airtight container for up to 2 months.