Sourdough French Toast Casserole
If you're craving a cozy breakfast that feels indulgent but is secretly simple, this egg-free sourdough French toast casserole is your dream come true. I made it with my homemade cinnamon sourdough bread, soaked in a silky custard thickened naturally with cornstarch—no eggs needed! It’s the perfect make-ahead dish for slow weekends or special mornings, with all the warm spice and tangy sourdough flavor baked into every bite.
Equipment
- 9 Inch Casserole
Ingredients
- 6 slices of sourdough bread
- 3 tablespoon Butter (unsalted)
- 1 tablespoon corn starch
- 1 teaspoon vanilla
- 1 teaspoon ground cinnamon
- 1 ½ cup whole milk
- ¼ cup brown sugar
- ¼ cup of condensed milk for serving (optional)
Instructions
Step 1: Making the Egg-Free Custard
- Combine all custard ingredients in a microwave-safe bowl: milk, cornstarch, brown sugar, vanilla and ground cinnamon.
- Whisk thoroughly until the cornstarch is fully dissolved to prevent lumps.
- Add butter cubes to the mixture.
- Microwave for 1 minute → remove and whisk vigorously.
- Microwave again for 1 minute → remove and whisk again (crucial step).
- Microwave for a final 1 minute (especially needed if using chilled butter). Note that the room temperature butter might only need 2 minutes total.
- Finished custard should be: Smooth and thick enough to coat the back of a spoon.
- Let the custard cool slightly before using to avoid soggy bread.
Step 2: Soaking the Sourdough Bread
- Cut sourdough bread into cubes of your preferred size.
- Arrange the cubes in a greased baking dish, overlapping each other slightly.
- Pour warm custard evenly over the bread cubes, ensuring it gets between pieces.
- Press the bread down gently to help absorption.
- Cover and refrigerate.* Best: Overnight for deep flavor and perfect texture. * Quick version: At least 4 hours if short on time.
Step 3: Baking Your Casserole
- Preheat oven to 350°F (175°C).
- Remove casserole from the fridge and let sit for about 20 minutes at room temperature.
- Bake uncovered for 25–30 minutes until the edges turn golden brown
- Cover loosely with foil for the final 10 minutes to prevent over-browning and ensuring the center cooks evenly.
- Final texture should be slightly crispy edges, custardy, tender center – the perfect contrast!
Step 4: Serving Your Sourdough French Toast Casserole
- After baking, allow casserole to rest for 15 minutes to help the custard set.
- Serve with sweetened condensed milk (for a decadent finish), or get creative with maple syrup, fresh berries or powdered sugar.
Notes
- Nailing the texture of an egg-free sourdough French toast bake starts with choosing the right bread. Day-old or slightly dried sourdough is ideal, as it soaks up the custard without falling apart. If you're working with fresh bread, let the slices air-dry for a few hours or lightly toast them to firm them up before layering.
- Activating cornstarch properly is key to getting that luscious custard. If your mixture still seems runny after microwaving, continue heating it in short 30-second bursts, whisking well after each, until it thickens enough to coat the back of a spoon. No microwave? You can easily cook the custard on the stove over medium heat—just stir constantly until it reaches the right consistency.
- Give it time to soak! That overnight rest in the fridge isn't just about saving time in the morning—it's what allows the bread to fully absorb the custard and develop rich, cohesive flavor. A dry casserole usually means it didn’t soak long enough, or there wasn’t quite enough custard to go around.
- Making it dairy-free? You can swap the whole milk with full-fat coconut milk or creamy oat milk, and replace the butter with your favorite plant-based option. Just keep in mind, thinner plant milks may need a little extra help—try adding an extra teaspoon of cornstarch to thicken things up.
- Watching the top brown too quickly? Just loosely cover your casserole with foil partway through baking to protect it. If you're aiming for more of that golden, caramelized finish, brushing the top with a bit of melted butter or sprinkling brown sugar in the last few minutes of baking will give it a gorgeous, toasty look.
- Looking to level up? A simple streusel topping adds crunch and decadence, or you can tuck in some fresh berries between the bread slices for a fruity twist. Just make sure to pat any fruit dry first—too much moisture can lead to a soggy casserole.
- Using gluten-free sourdough? No problem, but keep in mind it tends to soak up less liquid. Try cutting the custard back by about ¼ cup. For a festive touch—especially for brunches or special mornings—bake the casserole in muffin tins for adorable, single-serve portions that cook in about 20 to 25 minutes.
Nutrition
Calories: 225kcalCarbohydrates: 35.49gProtein: 5.88gFat: 6.72gSodium: 257mgPotassium: 147mgFiber: 1.1gSugar: 18.62gVitamin A: 229IUCalcium: 104mgIron: 1.52mg
Tried this recipe?Let us know how it was!