Bity
A sourdough french toast casserole is what happens in my kitchen when half a loaf has gone past its best and there are people staying. You cube the bread, pour custard over it, and half an hour later the oven does everything a frying pan would have done, only for six people at once.
The reason sourdough works so well is that stale, open crumb. It drinks the egg mixture without collapsing, so you get custardy pockets underneath and crisp, sugar-dusted corners on top. Soft sandwich bread turns to mush in the same dish.
Quick Breakdown
Why You’ll Love This Sourdough French Toast Casserole
- It rescues stale bread. Because dry cubes absorb more custard, day-old sourdough is genuinely better here than fresh.
- No standing at the stove. So nobody eats in shifts while the cook flips slices one at a time.
- Eight ingredients. Bread, eggs, milk, sugar, vanilla, cinnamon, salt, butter. Nothing unusual.
- Make it tonight, bake it tomorrow. Meanwhile the fridge does the soaking for you.
- Crisp edges, soft middle. In fact the corner pieces get fought over in this house.
Ingredient Notes
- Sourdough bread. Eight slices cut into cubes, about twelve cups. Slightly stale is ideal, and a proper open crumb soaks up more than a dense loaf.
- Eggs. Three large ones hold the whole thing together. Labels in the egg aisle are more confusing than they need to be, and the Academy of Nutrition and Dietetics translates them.
- Whole milk. Three quarters of a cup. Half milk and half cream makes it richer if you are feeling generous.
- Sugar. Only a tablespoon in the custard, since most of the sweetness comes from the syrup at the table.
- Cinnamon. Half a teaspoon, and it does a lot of work. Cleveland Clinic looks at what the spice actually does beyond flavour.
- Vanilla and salt. A teaspoon and a pinch. Salt is what stops the whole dish tasting flat and sweet.
- Butter. Two tablespoons for the dish. It also gives the base a fried edge as it bakes.
The Best Bread for a Sourdough French Toast Casserole
A rustic loaf with a chewy crust and irregular holes is the target. Those holes are what trap custard, and the crust keeps each cube in one piece instead of dissolving into the mixture.
Age matters as much as type. A day or two old is perfect. If your loaf is fresh, spread the cubes on a tray and dry them in a 300F oven for ten minutes, then let them cool before the custard goes on.
Brioche and challah also work in a sourdough french toast casserole style bake, though they are sweeter and softer, so cut back the sugar and the soak. Plain sandwich bread is the one to avoid, because it turns to paste.
Does It Have to Soak Overnight?
No. Twenty to thirty minutes on the counter is enough for the cubes to take up the custard, which is why this works as a same-morning breakfast.
An overnight rest in the fridge does improve it, though. The bread absorbs right through to the centre, so the texture goes from pleasant to properly custardy. Assemble it, cover it tightly, and bake it straight from cold the next morning with an extra five minutes.
Skipping the rest altogether is possible if you are in a hurry. Press the cubes down firmly into the liquid, wait while the oven heats, and accept a slightly drier result. That said, the twenty minute version is worth the wait.
How To Make Sourdough French Toast Casserole
1. Prepare the dish. First heat the oven to 350F and butter a baking dish generously, right up the sides.
2. Cube the bread. Then cut the slices into rough cubes, about an inch across, and tip them evenly into the dish.
3. Whisk the custard. Next whisk the eggs, milk, sugar, vanilla, cinnamon, and salt together until completely smooth with no streaks of white left.
4. Pour it over. After that, pour the mixture evenly across the surface rather than into one corner.
5. Press and wait. Press the cubes down gently with the back of a spoon so the top ones get wet too. Meanwhile leave it for twenty to thirty minutes.
6. Bake until set. Then bake for 30 to 35 minutes. The top should be golden and the centre should no longer wobble when you nudge the dish.
7. Cool slightly. Finally give it ten minutes out of the oven. It firms up as it settles, so cutting straight away gives you a looser slice.
Why Is the Middle Soggy?
- Not enough oven time. The most common cause. Give it another five to eight minutes and test the centre again.
- The bread was too fresh. Fresh crumb holds water rather than absorbing custard, so it never sets properly.
- The dish was too deep. A thick layer cooks from the outside in. Because of that, a wider, shallower dish bakes far more evenly.
- Too much liquid. Measure the milk rather than eyeballing it, since even a quarter cup extra changes the result.
- You cut it hot. The custard keeps setting as it cools, so ten minutes of patience earns you a cleaner slice.
Tips for the Best Sourdough French Toast Casserole
- Leave the crusts on. They are what gives the top its crunch.
- Butter the dish properly, corners included. Otherwise the caramelised edges weld themselves on.
- Cover with foil if the top browns before the centre sets. Then remove it for the last five minutes.
- A knife slid into the middle should come out clean. Of course a few moist crumbs are fine, but liquid is not.
- Dust the icing sugar on at the table. Do it early and it dissolves into the surface.
Storage and Reheating
- Fridge. Cover the sourdough french toast casserole and keep it for up to three days. It slices more neatly cold than warm.
- Freezer. Portion it, wrap each piece, and freeze for up to two months.
- Reheating. Ten minutes at 325F, covered loosely with foil. As a result the edges stay crisp instead of turning rubbery in the microwave.
Variations and Substitutions
- Berries. Scatter blueberries or raspberries between the cubes before the custard goes on.
- Apple and pecan. Thin apple slices and a handful of chopped pecans turn it into something closer to a pudding.
- A cinnamon loaf base. Swap the sourdough for slices of my bread machine cinnamon raisin bread and skip the ground cinnamon entirely.
- Richer. Replace half the milk with double cream. Still, it is already generous, so taste before you commit.
- Dairy free. Oat milk sets perfectly well, though the flavour is a little less round.
What to Serve With It for Brunch
A sourdough french toast casserole wants maple syrup, obviously, and a spoonful of thick yoghurt cuts through the sweetness. A batch of instant pot yogurt in the fridge means there is always some to hand.
For a fuller table, add something savoury and something crunchy. Sheet pan pancakes feel like overkill next to this, so I lean on a jar of homemade granola scattered over fruit instead, plus a pot of strong coffee.
Frequently Asked Questions
Bread and Assembly
Can I use sourdough for french toast casserole?
Yes, and it is the best choice. The chewy crust and open crumb hold their shape while soaking up custard, which softer loaves cannot manage.
Can I use stale bread?
Please do. Slightly stale sourdough absorbs the egg mixture without going mushy, so it gives a better texture than a fresh loaf.
Can I prepare it the night before?
Yes. Assemble the whole dish, cover it, and refrigerate overnight, then bake it in the morning with about five extra minutes.
Does it have to soak?
Twenty minutes is enough for a good sourdough french toast casserole. Skipping the soak gives you a drier bake, though it will still be perfectly nice.
Baking and Leftovers
How do I know when it is done?
A sourdough french toast casserole is ready when the top is golden and the centre no longer wobbles. A knife in the middle comes out clean, with moist crumbs but no liquid.
Can I add fruit?
Of course. Blueberries, raspberries, or thin apple slices all work. Add them between the cubes rather than on top, where they scorch.
How long does it keep?
Three days covered in the fridge, or two months frozen in portions. Reheat gently at 325F rather than in the microwave.
Ingredients
- 8 slices sourdough bread cut into cubes, about 12 cups
- 3 large eggs
- 3/4 cup whole milk
- 1 tablespoon granulated sugar
- 1 teaspoon vanilla extract
- 1/2 teaspoon ground cinnamon
- 1/4 teaspoon salt
- 2 tablespoons butter for greasing the baking dish
Instructions
- Preheat the oven to 350°F.
- Grease a baking dish generously with butter.
- Place the cubed sourdough bread evenly into the baking dish.
- In a bowl, whisk together the eggs, milk, sugar, vanilla extract, cinnamon and salt until smooth.
- Pour the egg mixture evenly over the bread cubes.
- Press the bread gently so the cubes absorb the liquid.
- Let the mixture sit for 20 to 30 minutes so the bread can soak up the custard. This improves the texture but can be skipped if you are short on time.
- Bake for 30 to 35 minutes until the top is golden and the centre is set.
- Allow to cool for ten minutes before serving.
