Name: Overnight French Toast Casserole Recipe
Prep time: 15 min
Cook time: 45 min
Ingredients: 1 loaf; 6 large eggs — the backbone of the custard; they set the bread and give structure.; 2 cups milk — richer milk means a creamier texture; don’t use ultra-lean milk or you’ll lose some of that custard feel.; ½ cup granulated sugar — just the right sweetness to balance the richer elements.; 1 tsp vanilla extract — for warm aromatic depth.; 1 tsp ground cinnamon — this gives that quintessential “French toast” flavour.; ¼ tsp ground nutmeg — subtle spice that pairs beautifully with cinnamon.; ¼ tsp salt — enhances all the other flavours (even in sweet dishes it matters.); ½ cup all-purpose flour — gives structure and bulk to the crumble.; ½ cup packed brown sugar — adds caramel-like richness and moisture.; 1 tsp ground cinnamon — echoes the cinnamon in the custard for cohesion.; ¼ tsp ground nutmeg — adds that spice continuity.; ⅛ tsp salt — balances the sweetness in the topping.; ½ cup cold butter (cut into small cubes — essential for a good crumble texture; don’t use melted butter.)

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Overnight French Toast Casserole Recipe | Easy & Delicious

I just pulled this Overnight French Toast Casserole Recipe out of the oven and I couldn’t wait to share it with you. There’s something extra cozy about waking up to the smell of cinnamon-brown sugar and bread soaked in eggs and milk — it’s the kind of breakfast I look forward to all week.

I prepped it the night before, slept soundly, and in the morning all I had to do was pop it in the oven. Whether you’re feeding a crowd or treating yourself, it hits that warm-and-comforting sweet spot.

If you love festive bakes, you can also enjoy this Christmas Tree Pull-Apart Bread Recipe for another holiday-inspired treat. Let’s dive in and I’ll walk you through everything: why this works, how to make it, and how you can tweak it to match your taste.

Ingredients

Here’s what you’ll need — I include some pro tips along the way so you understand why each ingredient matters for the best texture and flavour.

1 loaf (about 16-18 oz) French bread, challah or brioche — I recommend using slightly stale bread (one day old) so it absorbs the custard well without turning mushy.
6 large eggs — the backbone of the custard; they set the bread and give structure.
2 cups milk — richer milk means a creamier texture; don’t use ultra-lean milk or you’ll lose some of that custard feel.
½ cup granulated sugar — just the right sweetness to balance the richer elements.
1 tsp vanilla extract — for warm aromatic depth.
1 tsp ground cinnamon — this gives that quintessential “French toast” flavour.
¼ tsp ground nutmeg — subtle spice that pairs beautifully with cinnamon.
¼ tsp salt — enhances all the other flavours (even in sweet dishes it matters).

For the crumble topping:

½ cup all-purpose flour — gives structure and bulk to the crumble.
½ cup packed brown sugar — adds caramel-like richness and moisture.
1 tsp ground cinnamon — echoes the cinnamon in the custard for cohesion.
¼ tsp ground nutmeg — adds that spice continuity.
⅛ tsp salt — balances the sweetness in the topping.
½ cup cold butter, cut into small cubes — essential for a good crumble texture; don’t use melted butter.

Note: several servings

Variations

Want to mix it up or cater to dietary needs? Here are some ideas:

Dairy-free: Swap the milk for almond or oat milk, and use dairy-free butter for the crumble.
Sugar-reduced: Use coconut sugar or a sugar substitute for the custard and reduce the brown sugar in the topping by half.
Flavor add-ins: Toss in fresh berries or chopped apples into the bread layer; sprinkle chopped pecans or walnuts on top of the crumble for crunch.
Savoury twist: If you’d prefer less sweet, reduce the sugars, omit the nutmeg, skip the crumble and sprinkle grated sharp cheddar and herbs instead for a savoury bread pudding feel.
Spiced twist: Add a splash of orange extract or ½ tsp cardamom for an exotic spin.

You might also enjoy similar festive appetizers like this Cranberry Brie Bites Recipe — it’s a sweet and savory combo perfect for brunch tables.

Cooking Time

Here’s how the timing breaks down:

Prep Time: ~15 minutes
Cooking Time: ~45 minutes (or until the centre is set and the topping is golden)
Total Time: ~At least 2 hours including chilling (overnight is best)

Equipment You Need

A 9 × 13-inch baking dish (for even baking and correct custard depth)
Large mixing bowl (to whisk together eggs, milk, sugar and spices)
Medium bowl (for combine the crumble topping ingredients)
Pastry cutter (or two forks) to cut cold butter into the topping mixture
Whisk (for combining custard ingredients smoothly)

How to Make Overnight French Toast Casserole

Prepare the bread

First, tear or cut the bread into roughly one-inch pieces and spread it evenly in the greased baking dish. I prefer using slightly stale bread so it absorbs the liquid well without falling apart.

Mix the custard and soak the bread

In a large bowl whisk together the eggs, milk, sugar, vanilla, cinnamon, nutmeg and salt until thoroughly combined. Pour this mixture evenly over the bread, pressing down some pieces to ensure they’re submerged. Cover the dish and refrigerate for at least 2 hours, ideally overnight, to allow the flavours to meld and the bread to fully soak up the custard.

Make the crumble topping and bake

While the bread soaks, prepare the topping: in a medium bowl whisk flour, brown sugar, cinnamon, nutmeg and salt. Use a pastry cutter (or two forks) to cut the cold butter into the mixture until you have pea-sized clumps.

When ready to bake, pre-heat the oven to 350 °F, sprinkle the crumble evenly over the soaked bread, and bake for about 45 minutes or until the top is golden and the centre is set. Let it rest for a few minutes before slicing and serving.

Additional Tips for Making this Recipe Better

Here are a few things I learned while making this — helped me get better results:

I found that drying the bread for a few hours (or using day-old bread) made a big difference in avoiding a soggy bottom.
I like flipping a few bread pieces mid-soak so the bottom layer doesn’t stay dry or become overly mushy.
If the topping starts getting too dark while the centre still looks underdone, I cover the dish loosely with foil for the last 10 minutes of baking.
I always let it cool for 5-10 minutes post-bake — that short rest time helped it set properly and made slicing cleaner.
I experiment by adding a sprinkle of coarse sea salt on top just before serving — the sweet-salt contrast lifts the whole dish for me.

How to Serve Overnight French Toast Casserole

Serving this dish is fun and you can make it look extra special. I like to slice it into squares and arrange on warmed plates. Drizzle with maple syrup and a pat of butter or a dollop of whipped cream.

Fresh berries or sliced bananas sprinkled around the edges add colour and freshness. For presentation, you can dust a little powdered sugar on top and garnish with a sprig of mint. Serve with crisp bacon or sausage and a hot mug of coffee or tea, and you’ve got a breakfast (or brunch) that feels just a little bit fancy.

Nutritional Information

Just to give you an idea of what you’re eating:

Calories: ~325 kcal per serving (approx)
Protein: ~9 g
Carbohydrates: ~43 g
Fat: ~13 g

Make Ahead and Storage

Make ahead

Once you’ve assembled the dish and chilled it overnight, you’re good to go. The flavours deepen with time, and the soaking step means you can wake up and simply bake without much extra prep. It’s perfect for busy mornings or brunch with friends.

Storage

After baking, let the casserole cool slightly then cover and refrigerate in an airtight container. It will stay fresh for about 3-4 days. When reheating, I microwave individual portions 30-60 seconds until warm.

Freezing

You can freeze individual slices: wrap each piece tightly in plastic wrap, place in a freezer-safe bag, then freeze. When ready to serve, thaw overnight in the fridge then reheat in a 350 °F oven until warmed through (about 10-15 minutes).

Why You’ll Love This Recipe

Here are a few reasons this recipe stands out and why I think you’ll enjoy making (and eating) it:

It’s incredibly easy to assemble — almost no effort the morning of, because the soaking step is done overnight.
It’s versatile — you can adjust bread types, toppings, add-ins or dietary adaptations to suit tastes or restrictions.
It delivers that comforting, cozy flavour — warm cinnamon, nutmeg, sweet custard and a crunchy crumble topping all in one.
It’s perfect for gatherings — one dish serves many, so you don’t need to make separate portions of French toast.
It gives you a reason to prep ahead — freeing up your morning so you can relax or focus on other tasks.

I hope you enjoy making this Overnight French Toast Casserole as much as I did. It’s one of my favourite go-to brunch dishes when I want something comforting but also special. Let me know how it turns out — and feel free to tweak it and make it your own!

Ash Tyrrell