Eggnog French Toast Casserole (Overnight)

Christmas morning should smell like cinnamon and feel unhurried — which is exactly why this eggnog french toast casserole exists. You assemble it the night before, the bread soaks up a spiced eggnog custard overnight, and in the morning you slide it into the oven while the coffee brews. Forty-five minutes later, you’re pulling out a puffy, golden, custardy bake that tastes like the holidays decided to become breakfast.

I’ve made this every Christmas morning for years, and I’ve also made every mistake: soggy centers, burnt tops, custard that never set. The prep-ahead chart and ratios below are the result of all that delicious trial and error. This is the version that works.

Why You’ll Love This Recipe

• Overnight = stress-free Christmas morning. All the work happens the night before; the morning is just bake and enjoy.
• Real eggnog flavor. Not a hint, not a whisper — the custard is built on actual eggnog, spiked with extra nutmeg and vanilla.
• Custardy center, crisp edges. The overnight soak gives you that perfect bread-pudding texture contrast.
• Feeds the whole house. One 9×13 pan serves 8–10 — no standing at the stove flipping individual slices.
• Gorgeous with zero effort. It comes out of the oven looking like a magazine photo, especially with the brown-sugar topping.

Ingredients

For the casserole:

• 1 lb (about 16 oz) brioche or challah, cut into 1-inch cubes — Sturdy, enriched bread is essential. Brioche and challah soak up custard without disintegrating. Day-old or lightly stale bread is actually better — it absorbs more. Avoid soft sandwich bread; it turns to mush.
• 6 large eggs, room temperature
• 2 cups eggnog — Full-fat, good-quality eggnog. The store-bought kind works perfectly; this isn’t the place for light eggnog, which makes a watery custard. If your eggnog is very thick, that’s fine — it’s mostly cream and eggs anyway.
• 1/2 cup whole milk — thins the eggnog just enough for the bread to absorb it fully
• 1/3 cup packed brown sugar
• 2 tsp vanilla extract
• 1 tsp ground cinnamon
• 1/2 tsp freshly grated nutmeg — plus more for serving. Fresh nutmeg is dramatically more aromatic than pre-ground; if you only upgrade one spice this holiday season, make it this one.
• 1/4 tsp kosher salt

For the brown-sugar topping:

• 1/2 cup packed brown sugar
• 1/2 cup all-purpose flour
• 1 tsp ground cinnamon
• 1/2 cup cold unsalted butter, cubed
• 1/2 cup chopped pecans (optional but wonderful)

For serving: warm maple syrup, a dusting of powdered sugar, fresh nutmeg, whipped cream if you’re feeling celebratory.

Key tip — the bread-to-custard ratio. The magic ratio is roughly 1 lb of bread to 2 1/2 cups of total liquid (eggnog + milk) plus 6 eggs. Too much liquid and the center stays soupy; too little and it’s dry and bready. Weigh your bread if you can — “1 loaf” varies wildly between brands.

How to Make It

Step 1: Prep the bread (night before). Cut the brioche into 1-inch cubes. If your bread is fresh, spread the cubes on a sheet pan and let them sit out for a few hours (or toast at 300°F for 10 minutes) to dry slightly. Place the cubes in a greased 9×13-inch baking dish.

Step 2: Make the custard. In a large bowl, whisk the eggs until smooth. Whisk in the eggnog, milk, brown sugar, vanilla, cinnamon, nutmeg, and salt until the sugar dissolves and everything is uniform.

Step 3: Soak overnight. Pour the custard evenly over the bread cubes. Press gently with a spatula so every piece gets coated and starts absorbing. Cover tightly with plastic wrap or a lid and refrigerate at least 8 hours, or overnight up to 12 hours. The bread should look saturated and the custard mostly absorbed.

Step 4: Make the topping (night before or morning of). Combine the brown sugar, flour, and cinnamon. Cut in the cold butter until crumbly, then stir in the pecans. Refrigerate in a zip-top bag until baking time.

Step 5: Bake (Christmas morning). Take the casserole out of the fridge 30 minutes before baking to take the chill off. Preheat the oven to 350°F. Sprinkle the topping evenly over the casserole. Bake for 45–55 minutes, until puffed, deep golden brown, and set in the center — a knife inserted in the middle should come out mostly clean with no wet custard. If the top browns too quickly, tent loosely with foil for the last 15 minutes.

Step 6: Rest and serve. Let it rest 10 minutes — it deflates slightly and finishes setting. Serve warm with maple syrup, powdered sugar, and a snowfall of fresh nutmeg.

If you love a cozy make-ahead holiday breakfast, this pairs beautifully in a brunch spread with my Sweet Potato Casserole with Pecan Streusel holding down the savory-sweet side of the table.

Pro Tips

Prep-ahead chart:

More hard-won wisdom:

• The overnight soak is non-negotiable. I’ve tested a 2-hour soak versus overnight, and there’s no comparison — overnight gives you that uniform, custardy, bread-pudding texture. Short soaks leave dry bread pockets.
• Don’t skip the room-temp rest. Baking straight from the fridge adds 10–15 minutes and bakes unevenly — burnt edges, soupy middle. Thirty minutes on the counter fixes it.
• My soggy-center disaster: One year I doubled the eggnog “for extra custard” and the center never set, even after an extra 20 minutes. Respect the ratio — 2 1/2 cups liquid per pound of bread.
• Tent with foil. The brown-sugar topping caramelizes fast. If it’s deeply brown at 30 minutes but the center isn’t set, tent it — the inside still needs time.
• Fresh nutmeg matters. Pre-ground nutmeg loses its volatile oils within months. A whole nutmeg and a microplane costs a few dollars and transforms this dish.

Variations

• Chocolate chip: Fold 1 cup of chocolate chips into the bread cubes — the kids’ table favorite.
• Cranberry-orange: Add 1 cup of fresh cranberries and 1 tablespoon of orange zest to the bread layer for a tart, festive twist.
• Apple-cinnamon: Layer in 2 diced apples tossed with cinnamon — very apple-pie-for-breakfast.
• Rum-spiked: Add 2 tablespoons of dark rum to the custard for the adults’ servings.
• Dairy-free: Use dairy-free eggnog (several brands make it now) and vegan butter in the topping. The texture is slightly less rich but still delicious.
• Individual ramekins: Divide among buttered ramekins and bake 25–30 minutes — elegant for a smaller gathering.

Storage & Meal Prep

• Refrigerator: Leftovers keep 3–4 days, covered. The topping softens but reheats well.
• Freezer: Freeze baked portions up to 2 months. Thaw overnight in the fridge.
• Reheating: Warm individual portions in the microwave, or reheat the whole dish at 325°F for 15–20 minutes covered with foil. A quick 2-minute broil re-crisps the topping.
• Make-ahead limits: Don’t assemble more than 12 hours ahead — beyond that, the bread breaks down too much and the texture suffers.

FAQs

Can I use regular sandwich bread?
I don’t recommend it — soft sandwich bread disintegrates during the overnight soak. If it’s all you have, reduce the soak to 4–6 hours and expect a softer, more pudding-like result.

My center is still wet but the top is burning. What do I do?
Tent tightly with foil and keep baking — the center needs more time. Next time, make sure the casserole rested at room temperature before baking, and verify your oven temperature with a thermometer.

Can I make this without eggnog?
You can substitute 2 cups of half-and-half plus an extra 1/2 teaspoon of nutmeg and 1/4 cup more brown sugar — but then it’s just a (delicious) regular french toast casserole. The eggnog is the point here.

Is store-bought eggnog okay?
Absolutely — that’s what I use. Choose full-fat eggnog from a brand you like drinking; the flavor comes straight through.

Can I prep this two nights ahead?
I wouldn’t — 8 to 12 hours is the sweet spot. Beyond 12 hours the bread gets mushy.

What do I serve with eggnog french toast casserole?
Crispy bacon or breakfast sausage for salty contrast, fresh fruit to cut the richness, and lots of coffee. For a bigger brunch spread, my fluffy cottage cheese pancakes or copycat egg bites round it out nicely.

If you enjoyed this recipe, you’ll also love my 15-Minute Peanut Butter Noodle Stir-Fry with Frozen Vegetables.

Christmas morning deserves a breakfast that practically makes itself — and once you’ve tasted this, you might find yourself making a second holiday-morning tradition out of my Sweet Potato Casserole with Pecan Streusel reheated alongside it.