Sourdough French Toast Casserole (Make-Ahead Breakfast Bake)

If you want a brunch bake that looks impressive but is mostly hands-off, this sourdough French toast casserole is it. Cubes of sourdough soak up a rich vanilla custard and bake up golden on top with a soft, custardy center. The brown sugar cinnamon swirl tastes like a baked-in cinnamon roll, and the streusel topping takes it to another level. If you’ve tried my Brioche French Toast Casserole or Brioche French Toast Casserole, you already know I don’t miss with sweet breakfast casserole recipes.

Why You'll Love This French Toast Casserole Recipe

This is my go-to make-ahead breakfast or brunch when I want a guaranteed win. Sourdough is the perfect bread for baked French toast because it’s sturdy and crusty, so it holds onto the custard without turning into mush. You get clean slices, a tender center, and that slightly crisp top that makes people go back for seconds.

The brown sugar cinnamon layer is what really makes it special. It bakes right into the middle, so every bite has that warm cinnamon-sugar flavor without needing a complicated topping. It’s the kind of breakfast that works for holidays, houseguests, birthdays, or any weekend when you want something cozy and crowd-pleasing.

And the leftovers are unreal. Once it chills and you reheat it, it turns almost bread pudding-like in the best way. Add maple syrup, powdered sugar, or a pat of butter, and it somehow tastes even better the next day.

Ingredients You'll Need

Bread Base:

• 500 to 600 grams crusty sourdough bread, cut into 1-inch chunks (about ½ loaf)

Cinnamon Sugar Filling:

• ¼ cup unsalted butter, softened
• ¾ cup brown sugar
• 1 tablespoon ground cinnamon
• ¼ teaspoon salt

Egg Mixture:

• 5 large eggs
• ¾ cup heavy cream
• 1 cup whole milk
• ⅓ cup granulated sugar
• 1 teaspoon vanilla extract
• ½ teaspoon salt

Streusel Topping (optional):

• ⅓ cup brown sugar
• ⅓ cup all-purpose flour
• 3 tablespoons unsalted butter
• 2 teaspoons ground cinnamon
• ½ cup chopped pecans (optional)

Ingredient Notes That Make This Recipe Work

• A few day-old sourdough matters. Stale bread soaks up custard like a sponge without collapsing. If your bread is fresh, I’ll show you how to dry it out fast in the oven.
• Heavy cream + milk is the sweet spot. Cream gives richness. Milk keeps the custard from feeling too heavy. Together, they make that bakery-style texture.
• Salt is not optional. Salt in the filling and custard balances the sugar and makes the cinnamon flavor pop. Without it, baked French toast can taste flat.
• The cinnamon sugar filling is the “wow” layer. It melts into the bread as it bakes, creating pockets of gooey cinnamon sweetness.
• Streusel is optional but worth it. If you want a crunchy top, streusel gives you that crisp, caramelized finish that makes people go back for seconds.

How to Make Sourdough French Toast Casserole

Step 1: Cube the bread

The night before baking, cut the sourdough into 1-inch cubes. You want big chunks, not tiny pieces. Put back in the bread bag or into an airtight container. If your bread is not day-old: Spread cubes on a sheet pan and bake at 300°F for 10-15 minutes, tossing once, until the outside feels dry but not toasted.

Step 2: Make the cinnamon sugar filling

In a small bowl, mix softened butter with brown sugar, cinnamon, and salt until a thick cinnamon-sugar butter forms.

Step 3: Layer the bread and filling

Grease a 10-12-inch skillet or a 9x13-inch baking dish. Add half the bread cubes. Spoon most of the cinnamon-sugar mixture over the bread. Add the remaining bread on top and dollop the rest of the mixture on top. Do not stress about perfect coverage. As it bakes, the filling melts and spreads.

Step 4: Whisk the custard (egg mixture)

In a large bowl, whisk eggs, heavy cream, milk, granulated sugar, vanilla, and salt until smooth and combined.

Step 5: Pour, press, and chill overnight

Pour the custard evenly over the bread. Use a spatula or the back of a spoon to gently press the bread down so the top layer gets soaked too. Cover tightly with plastic wrap and refrigerate for 8-10 hours.

Step 6: Add streusel (optional)

Right before baking, make the streusel. Mix brown sugar, flour, butter, cinnamon, and pecans (if using) until crumbly. Sprinkle evenly over the casserole.

Step 7: Bake

Preheat your oven to 350°F. Bake for about 40 minutes, until golden, bubbly, and set in the center. The center should jiggle slightly but not look wet. If the top browns too fast, loosely tent with foil for the last 10 minutes.

Step 8: Rest and serve

Let it rest 10 minutes before serving. This helps the custard finish setting, so slices hold together. Serve warm with maple syrup, powdered sugar, fresh berries, or whipped cream.

Pro Tips for the Best French Toast Casserole

Variations To Try

• Blueberry sourdough French toast casserole: Add 1½ cups blueberries (fresh or frozen) between the bread layers. If using frozen, do not thaw. For best distribution, sprinkle ¾ cup over the middle layer and ¾ cup over the top layer before pouring on the custard.
• Apple cinnamon version: Use 2 medium apples (Honeycrisp or Granny Smith), thinly sliced. Toss with 1 tablespoon brown sugar and 1 teaspoon cinnamon, then layer the apples between the bread cubes (spread them out so they don’t clump). If you want extra apple flavor, add ½ teaspoon vanilla to the apple toss.
• Cream cheese swirl: Cut 6 ounces of cream cheese into small cubes. Scatter the cubes between the bread layers to create pockets throughout. If you want it extra “cheesecake,” bump it to 8 ounces. It'll give it a stuffed French toast vibe.
• No streusel version: Skip the streusel entirely. After baking, dust with 2–3 tablespoons powdered sugar and serve with maple syrup. If you want a little crunch without streusel, sprinkle ¼ cup chopped pecans on top before baking.
• Extra tangy sourdough: Use a very tangy loaf (older sourdough works great). No ingredient changes needed, just a more fermented loaf for stronger sourdough flavor that balances the sweet custard.

Sourdough French Toast FAQs

Why use sourdough bread for French toast casserole?

Sourdough is sturdy, so it absorbs custard without turning to mush. It also adds a subtle tang that balances the sweetness and makes the whole casserole taste less sugary and more bakery-style.

Can I make this without heavy cream?

Yes. You can replace the heavy cream with more whole milk or creamy oat milk, but the casserole will be a little less rich. Half-and-half is a great middle-ground option that still gives you a creamy texture.

Can I use very fresh sourdough?

Yes, but it helps to dry it out first. Fresh bread can turn gummy. Cube it and let it sit out 30–60 minutes (or toast lightly) before assembling so it soaks the custard better.

How do I know when sourdough French toast casserole is done?

The top should be golden brown, the edges should be bubbling, and the center should look set. A slight jiggle in the very middle is fine, but it shouldn’t look wet or sloshy. If the top is browning before the center is set, tent with foil and bake a little longer.

Do I have to chill it overnight?

Overnight gives the best custardy texture, but you can chill it for at least 4 hours in a pinch. The longer soak helps the custard absorb evenly, so you don’t get dry bread on top and soggy bread on the bottom.

Can I use a different pan than a 9x13?

Yes. A 10 or 12-inch oven-safe skillet works great, but you can really use any pan. If you use a smaller, deeper dish, plan on a longer bake time. If you use a larger, shallower pan, it may bake faster. Use doneness cues, not just time.

Storage, Reheating, and Make-Ahead Tips

• Refrigerator: Store the baked casserole covered in the fridge for up to 4 days.
• Reheating: For quick reheating, microwave individual slices for 20–30 seconds. For the best texture (crisp top, custardy center), reheat in a 350°F oven for about 5 minutes or until warmed through.
• Freezing: Freeze individual slices wrapped tightly for up to 2 months. Thaw overnight in the fridge, then reheat in the oven for the best texture.
• Make-ahead (easiest plan): You can cube the bread and store it in a bag a day ahead. Make the streusel ahead and refrigerate it. Assemble the casserole the night before and bake it in the morning. If baking straight from the fridge, that’s totally fine, just watch the center and add about 5 extra minutes if needed.

My Final Thoughts

This sourdough French toast casserole is everything you want in an overnight breakfast. Crispy top, soft custardy center, cinnamon sugar pockets throughout, and a streusel that takes it over the top. It is easy, reliable, and perfect for feeding a crowd without standing at the stove flipping slices of bread all morning. Prep it the night before, bake it in the morning, and enjoy that bakery brunch at home with minimal effort. Make this delicious French toast casserole and leave me a comment and review below so I can hear what you think.

Sweet Breakfast Casserole Recipes to Try Next

• Cinnamon roll French toast
• Pioneer Woman French toast casserole
• Cinnamon roll casserole
• Pancake casserole

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Yield: 8 servings

Sourdough French Toast Casserole (Make-Ahead Breakfast Bake)

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If you want a brunch bake that looks impressive but is mostly hands-off, this sourdough French toast casserole is it. Cubes of sourdough soak up a rich vanilla custard and bake up golden on top with a soft, custardy center. The brown sugar cinnamon swirl tastes like a baked-in cinnamon roll, and the streusel topping takes it to another level. It feeds a crowd, makes the kitchen smell unreal, and if you’ve tried my Challah French Toast Casserole or Brioche French Toast Casserole, you already know I don’t miss with sweet breakfast casserole recipes.

Prep Time 20 minutes

Cook Time 40 minutes

Additional Time 8 hours

Total Time 9 hours

Ingredients

Bread Base:

• 500 to 600 grams crusty sourdough bread, cut into 1-inch chunks (about ½ loaf)

Cinnamon Sugar Filling:

• ¼ cup unsalted butter, softened
• ¾ cup brown sugar
• 1 tablespoon ground cinnamon
• ¼ teaspoon salt

Egg Mixture:

• 5 large eggs
• ¾ cup heavy cream
• 1 cup whole milk
• ⅓ cup granulated sugar
• 1 teaspoon vanilla extract
• ½ teaspoon salt

Streusel Topping (optional but worth it):

• ⅓ cup brown sugar
• ⅓ cup all-purpose flour
• 3 tablespoons unsalted butter
• 2 teaspoons ground cinnamon
• ½ cup chopped pecans (optional)

Instructions

1. The night before baking, cut day-old sourdough bread into 1-inch cubes and set aside.

2. In a small bowl, mix softened butter with brown sugar, cinnamon, and a pinch of salt to create a cinnamon-sugar butter.

3. Add half of the bread cubes to a greased 10–12 inch skillet or 9x13-inch baking dish. Spoon most of the cinnamon-sugar mixture over the bread. Layer the remaining bread on top and dollop with the rest of the mixture.

4. In a separate bowl, whisk together eggs, heavy cream, milk, granulated sugar, vanilla extract, and a pinch of salt. Pour the mixture evenly over the bread.

5. Cover with plastic wrap and refrigerate for 8–10 hours to soak.

6. Optional topping: Mix brown sugar, flour, butter, cinnamon, and chopped pecans to make a streusel. Sprinkle over the top just before baking.

7. Preheat the oven to 350°F (175°C). Bake the casserole for about 40 minutes, until golden, bubbly, and set in the center.

8. Serve warm. Enjoy!

Nutrition Information:

Yield:

8

Serving Size:

1
Amount Per Serving: Calories: 565Total Fat: 35gSaturated Fat: 15gUnsaturated Fat: 20gCholesterol: 175mgSodium: 279mgCarbohydrates: 59gFiber: 4gSugar: 47gProtein: 8g