King Cake Overnight French Toast

My kitchen smelled like cinnamon and butter at 6 a.m. when I pulled this golden casserole from the oven, and I realized I'd accidentally created my favorite Mardi Gras breakfast tradition. A friend had mentioned she wanted something festive but effortless for a brunch party, and somehow layers of custard-soaked brioche with cream cheese swirled through felt like the answer. The best part? I'd assembled it the night before while sipping coffee, letting the fridge do most of the work. When it emerged puffed and caramelized, with those jewel-toned sprinkles catching the morning light, everyone at the table went quiet for a moment. That's when I knew this dish was special.

I made this for a group of friends who showed up on a gray January morning, and by the time we finished eating, someone had started planning the next brunch around this exact dish. One friend went back for thirds and said it tasted like celebration, which I think is the highest compliment a breakfast casserole could receive. That's when I understood that feeding people something warm and purposeful first thing in the morning changes the entire tone of the day.

Ingredients

• Brioche or challah, 1 large loaf cut into 1-inch cubes: This bread is custardy on the inside and holds up beautifully when soaked; avoid standard sandwich bread, which turns mushy.
• Eggs, 6 large: The custard base that transforms the bread into something rich and custardy; room temperature eggs mix more evenly.
• Whole milk and heavy cream, 2 cups and 1 cup: The cream adds luxurious richness while milk keeps it from being too dense; don't skimp on either.
• Granulated sugar and light brown sugar, ¾ cup and 2 tbsp: Brown sugar adds depth and slight caramel notes that complement the spices beautifully.
• Vanilla extract, cinnamon, nutmeg, 2 tsp, 2 tsp, ¼ tsp: These warm spices are what make people close their eyes and smile; pure vanilla is worth the extra cost here.
• Cream cheese, softened, 4 oz: This creates sweet pockets of flavor throughout and adds subtle tang that balances the sugar.
• Powdered sugar for filling, ⅓ cup: This dissolves into the cream cheese smoothly, creating a spreadable mixture.
• Unsalted butter and cinnamon sugar topping, 2 tbsp and 2 tbsp sugar with 1 tsp cinnamon: This caramelizes during baking and adds a crispy-sweet finish that's addictive.
• Powdered sugar, milk, and vanilla for icing, 1 cup, 2-3 tbsp, ½ tsp: The icing should be loose enough to drizzle but thick enough to coat; adjust milk gradually.
• Purple, green, and gold sanding sugars or sprinkles: These are non-negotiable for that festive King Cake look; use actual sanding sugar for better texture than regular sprinkles.

Instructions

Prepare your dish:

Butter a 9x13-inch baking dish generously, making sure to coat the corners and sides so nothing sticks. This moment of preparation actually matters more than people realize.

Make the cream cheese layer:

Beat softened cream cheese with powdered sugar until completely smooth, then fold in lemon zest if using. The lemon stays subtle but adds brightness that cuts through the richness.

Build your layers:

Spread half the bread cubes across the prepared dish in a single layer, then dollop the cream cheese mixture evenly across them. Top with remaining bread cubes, pressing gently so they nestle together without crushing.

Create the custard:

Whisk eggs, milk, cream, sugars, vanilla, and spices in a large bowl until completely combined and the sugar has mostly dissolved. You'll see specks of cinnamon and nutmeg floating throughout, which is exactly right.

Soak overnight:

Pour custard slowly and evenly over the bread, using a gentle hand to press it down so all the cubes drink it in. Cover tightly with foil and refrigerate for at least 8 hours, preferably overnight; this is when the magic happens.

Prepare for baking:

Remove the dish from the refrigerator about 30 minutes before baking, allowing it to come to room temperature while your oven preheats to 350°F. This ensures even cooking throughout.

Add the cinnamon sugar topping:

Mix melted butter with sugar and cinnamon, then drizzle evenly across the entire surface. This layer will caramelize and become irresistibly crispy.

Bake until golden:

Bake uncovered for 40 to 45 minutes, until the top is puffed and deeply golden brown and a knife inserted in the center comes out mostly clean. The center will still have a slight jiggle, and that's perfect.

Cool briefly:

Let it rest for 10 minutes on the counter so the custard sets just enough to hold together when served. This is a good moment to make the icing.

Make and drizzle the icing:

Whisk powdered sugar, milk, and vanilla until smooth and pourable, then drizzle generously over the warm casserole. Immediately sprinkle the purple, green, and gold sugars in festive stripes before the icing sets.

Serve and celebrate:

Bring it to the table warm and watch people's faces light up. This dish deserves to be shared the moment it's ready.

Save

The first time someone told me this tasted like a hug, I realized I'd been thinking about breakfast all wrong. It's not just about fuel; it's about creating a moment where everyone slows down and remembers that good food tastes better when you're not rushing. This dish does that naturally, almost without trying.

Why Overnight Soaking Changes Everything

When I first made French toast casserole, I made the rookie mistake of baking it immediately after assembling it, and the bread stayed too firm while the bottom got soggy. The overnight soak is actually the secret weapon here; it gives the brioche time to absorb the custard evenly from every angle, transforming it into something almost cloud-like. The cream cheese filling also has time to soften and disperse slightly, creating those sweet pockets throughout. By morning, you're not baking bread anymore; you're setting custard, which is a completely different texture outcome.

Making It Your Own

Once I understood the basic structure, I started experimenting with what could go between those bread layers. Cinnamon swirl brioche is phenomenal if your bakery carries it, but I've also used regular brioche with extra cinnamon mixed into the custard itself. Pecans scattered between the layers add a nutty crunch that plays beautifully against the soft interior; I now do this almost every time. The icing is where you can have real fun too; some mornings I skip the food coloring entirely and just keep it white, while other times I lean into the King Cake theme completely.

Scaling and Storage

I've never successfully halved this recipe because the 9x13 dish is such a specific size, and honestly, it's made eight servings for a reason. Leftovers actually taste better the next day, somehow richer and more set, which means you can prepare this two days ahead if needed. Store any remainder covered in the refrigerator for up to three days, though it rarely lasts that long in my house. To reheat, cover loosely with foil and warm at 300°F for about 15 minutes until heated through but not scorched.

• Plan to assemble this the night before, which means your morning is actually relaxed instead of chaotic.
• If you're feeding a smaller group, this freezes beautifully after baking but before icing; thaw overnight and ice the next morning.
• The icing really should go on while the casserole is still warm so it creates that glossy, pourable finish that looks bakery-quality.

Save

This casserole has become my answer to the question, what do you make when you want to say 'I'm so glad you're here' through breakfast? It's festive without being fussy, impressive without being stressful, and absolutely worth the advance planning. Make it this weekend and watch what happens.

Recipe FAQ

→ Can I use bread other than brioche?

Yes, challah or other soft, slightly sweet breads work well for soaking the custard and achieving a tender texture.

→ Is overnight soaking necessary?

Overnight soaking allows the custard to fully penetrate the bread, resulting in a moist, custardy center and better flavor melding.

→ How can I make it dairy-free?

Substitute plant-based milks and dairy-free cream cheese alternatives to keep the creamy texture without dairy ingredients.

→ What’s the best way to get the topping crispy?

Drizzling the butter, sugar, and cinnamon mixture evenly before baking helps create a golden, slightly crisp finish on top.

→ Can nuts be added to this dish?

Adding chopped pecans between bread layers offers a delightful crunch and nutty flavor that complements the custard base.