Sourdough French Toast Casserole

Welcome to the ultimate comfort breakfast—Sourdough French Toast Casserole! This make-ahead breakfast bake is buttery, custardy, and perfectly golden on top. Whether you're using fresh or leftover sourdough bread, this dish is guaranteed to be a hit for lazy weekends, holiday mornings, or busy brunches.

In this post, I’ll walk you through exactly how to make sourdough French toast casserole from scratch, including:

• Why sourdough bread is perfect for French toast casserole

• How to make it ahead of time (and even freeze it!)

• Simple variations (like blueberry lemon, apple cinnamon, or chocolate chip)

• FAQs and troubleshooting

• Plus tips for making it dairy-free or gluten-free!

This sourdough breakfast bake is cozy, custardy, and incredibly easy to prepare in advance. Let’s make breakfast magical!

Why You'll Love This Sourdough French Toast Casserole

If you’ve ever had classic French toast and thought, “This would be even better as a casserole,” you’re in the right place. Here’s why this recipe is a breakfast game-changer:

• Uses up sourdough bread: Stale sourdough is perfect for soaking up the rich custard.

• No standing at the stove: No flipping, no fuss—just mix, bake, and enjoy.

• Perfect for holidays & crowds: Ideal for Easter, Christmas morning, or when guests stay over.

• Customizable flavors: Add berries, chocolate, or your favorite spices.

Ingredients You’ll Need

Here’s what you need to make the ultimate sourdough French toast casserole:

For the Casserole Base:

• 1 loaf sourdough bread (about 1 lb), cut into 1-inch cubes

• 8 large eggs

• 2 ½ cups whole milk (or a dairy-free alternative)

• ½ cup heavy cream (or full-fat coconut milk for dairy-free)

• ¾ cup brown sugar

• 2 tsp vanilla extract

• 1 tsp ground cinnamon

• ¼ tsp nutmeg

• ¼ tsp salt

For the Topping:

• ½ cup all-purpose flour

• ½ cup brown sugar

• 1 tsp ground cinnamon

• ¼ tsp salt

• ½ cup cold butter, cubed

Optional mix-ins:

• 1 cup blueberries

• 1 apple, peeled and diced

• ½ cup chocolate chips

• ½ cup chopped pecans

Choosing the Best Bread for French Toast Casserole

While any sturdy bread works, sourdough adds the perfect tang and texture to balance the sweet custard. It holds up to soaking overnight without falling apart. Use homemade sourdough, store-bought artisan loaves, or even sourdough discard sandwich bread!

Tip: Day-old or slightly stale sourdough works best—fresh bread can become mushy.

How to Make Sourdough French Toast Casserole (Step-by-Step)

Step 1: Cube the Bread

Cut your sourdough loaf into bite-sized cubes, about 1-inch thick. If it’s freshly baked, leave the cubes out for an hour or two to dry slightly.

Step 2: Make the Custard

In a large mixing bowl, whisk together eggs, milk, cream, brown sugar, vanilla, cinnamon, nutmeg, and salt.

Step 3: Combine and Soak

Grease a 9x13-inch baking dish and spread the sourdough cubes evenly. Pour the custard mixture over the bread. Gently press down with a spatula to ensure all the bread soaks up the liquid.

Optional: Sprinkle in your favorite mix-ins at this point (berries, apples, nuts, etc.).

Step 4: Make the Streusel Topping

In a separate bowl, combine flour, brown sugar, cinnamon, and salt. Cut in the cold butter with a pastry cutter or your fingers until crumbly. Cover and refrigerate.

Step 5: Chill Overnight (or Bake Now)

Cover the casserole and refrigerate for at least 4 hours or overnight. This allows the bread to fully absorb the custard.

Want it same-day? Let it sit for at least 30 minutes before baking.

Step 6: Bake

Preheat oven to 350°F (175°C). Sprinkle the chilled streusel topping evenly over the soaked casserole. Bake uncovered for 45–55 minutes, or until the center is set and the top is golden.

Serving Suggestions

Serve warm with a drizzle of maple syrup, whipped cream, or a dusting of powdered sugar. Here are a few flavor combinations you’ll love:

• Berry Bliss: Blueberries + lemon zest + powdered sugar

• Apple Pie: Diced apples + extra cinnamon + caramel drizzle

• Choco-lovers: Chocolate chips + mini marshmallows (bake uncovered for a s'mores effect!)

Make-Ahead & Freezing Tips

To Make Ahead:

Prepare the casserole and streusel, cover tightly, and refrigerate for up to 24 hours before baking.

To Freeze:

Assemble (without streusel) in a freezer-safe dish. Wrap in plastic, then foil. Freeze for up to 2 months. Thaw overnight in the fridge, top with streusel, then bake.

To Reheat:

Microwave individual portions for 1–2 minutes or reheat the entire dish in the oven at 325°F for 15–20 minutes.

Customization Ideas

Want to change it up? Here are some delicious variations:

1. Sourdough French Toast Casserole with Cream Cheese

• Add dollops of cream cheese between the bread cubes before soaking for extra richness.

2. Pumpkin Spice French Toast Bake

• Replace ½ cup of the milk with pumpkin purée and add 1 tsp pumpkin pie spice.

3. Savory Sourdough French Toast Casserole

• Omit sugar and vanilla, add cooked sausage, cheddar, and chives. Bake as directed!

Troubleshooting & FAQs

My casserole is soggy—what happened?

It may have been underbaked or the bread was too fresh. Use day-old bread and ensure it bakes until the center is set.

Can I use sourdough discard?

Not for the bread cubes, but if you're making your own sourdough bread ahead of time, it's a great use of discard!

Can I use almond or oat milk?

Yes! Just swap it in 1:1 for dairy milk. For creaminess, use canned coconut milk or a dairy-free creamer.

Can I reduce the sugar?

You can cut the sugar in the custard to ½ cup if you prefer it less sweet—especially if serving with syrup.

Nutrition Info (Approximate, per serving):

• Calories: 350

• Protein: 9g

• Carbs: 40g

• Fat: 18g

• Sugar: 18g

• Fiber: 2g

Based on 12 servings, using whole milk and brown sugar.

Reader Reviews

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“This is my new go-to for holidays! I made it with blueberries and it was amazing. The sourdough gives such a great flavor.” – Emily R.

⭐⭐⭐⭐⭐
“I love that I can make it the night before. I used almond milk and it turned out perfectly. My kids devoured it!” – Danielle T.

⭐⭐⭐⭐⭐
“Made it with apple and cinnamon for Thanksgiving morning. HUGE hit. I added a little maple syrup to the custard—so good.” – Mark W.

Final Thoughts

This sourdough French toast casserole is a must-try whether you’re feeding a family, hosting guests, or just want a cozy weekend breakfast. It’s simple to make, packed with flavor, and the kind of recipe you’ll turn to again and again.

Don’t forget to share your version on Pinterest or Instagram and tag me—I love seeing your delicious bakes!