King Cake Overnight French Toast

There's something about the morning before Mardi Gras that makes everything feel like a celebration waiting to happen. A few years back, I wanted to capture that festive feeling in a breakfast dish, and instead of just making King Cake, I thought: why not turn it into something you can prep the night before? The result was this overnight French toast bake, where layers of buttery brioche cradle a sweet cream cheese filling, all soaked in a spiced custard that somehow tastes even better after sitting in the fridge overnight. The real magic happens when it comes out of the oven golden and puffy, then gets crowned with that signature royal icing and those colorful sanding sugars that make you smile just looking at it.

I made this for the first time when my sister texted asking if I could do something "fun and Mardi Gras-y" for a Sunday brunch with her friends. I was nervous about whether soaking it overnight would make it soggy instead of custardy, but the moment that icing hit the warm cake and started dripping down the sides in those purple, green, and gold streaks, everyone at the table actually gasped. That's when I knew this recipe had staying power.

Ingredients

• Brioche or challah (1 large loaf, cut into 1-inch cubes): The richness here is essential; avoid sandwich bread because it'll turn to mush rather than soak evenly.
• Eggs (6 large): They're what transforms this from bread pudding into something custardy and custard-like.
• Whole milk and heavy cream (2 cups and 1 cup): The combination of both creates that creamy, almost luxurious texture that just coats your mouth.
• Granulated and brown sugars (¾ cup and 2 tbsp): Brown sugar adds a subtle molasses depth that makes people wonder what your secret is.
• Vanilla extract, cinnamon, nutmeg (2 tsp, 2 tsp, ¼ tsp): These warm spices are what make it feel like Mardi Gras morning instead of just another breakfast.
• Cream cheese (4 oz, softened): This creates those pockets of tangy sweetness sandwiched between bread layers; let it come to room temperature or it won't spread evenly.
• Powdered sugar for filling and icing: The filling uses ⅓ cup, while the icing uses 1 cup; don't mix them up or your topping will be too thick or too thin.
• Unsalted butter, sugar, and cinnamon for the topping (2 tbsp, 2 tbsp, 1 tsp): This creates a subtle crunch right before the icing hits.
• Purple, green, and gold sanding sugars: Use actual sanding sugar if you can find it, not regular sprinkles; it holds its color and texture better.

Instructions

Prepare your vessel:

Grease a 9×13-inch baking dish with butter or cooking spray, making sure you get into all the corners so nothing sticks.

Make the cream cheese filling:

Beat softened cream cheese with powdered sugar and lemon zest (if using) until it's smooth and spreadable. The lemon zest adds a brightness that keeps the whole thing from feeling too heavy.

Layer the bread:

Arrange half your bread cubes across the bottom of the dish, then dollop the cream cheese mixture evenly over them, and top with the remaining bread cubes. Don't worry if it looks haphazard; the custard will fill all the gaps.

Whisk the custard:

In a large bowl, whisk together eggs, milk, cream, both sugars, vanilla, cinnamon, nutmeg, and salt until everything is well combined and there are no streaks of egg white. This is your liquid gold.

Soak and chill:

Pour the custard evenly over the bread mixture and press down gently with a spatula to help it absorb, then cover tightly with foil and refrigerate overnight (at least 8 hours, but up to 24 is fine). This waiting is when all the flavors meld and the bread becomes impossibly tender.

Start the oven:

The next morning, preheat your oven to 350°F and let the baking dish sit on the counter while it heats; bringing it closer to room temperature helps it bake more evenly.

Add the final cinnamon sugar:

Mix melted butter with sugar and cinnamon, then drizzle it over the casserole in a light zigzag pattern, not drenching it.

Bake until golden:

Bake uncovered for 40 to 45 minutes, until the top is puffed and golden brown and a knife inserted near the center comes out clean. Your kitchen will smell like cinnamon and butter in a way that feels almost unfair to the rest of the day.

Cool slightly:

Let it rest for about 10 minutes; this helps it set so it slices better and the icing doesn't slide right off.

Finish with the festive icing:

Whisk powdered sugar, milk, and vanilla until you get a consistency that's thick but still pourable, then drizzle it over the warm casserole and immediately sprinkle with your purple, green, and gold sanding sugars in festive stripes before the icing sets.

Serve and celebrate:

Serve warm while the icing is still glossy and the inside is still custardy.

Pin this

What got me about this dish was watching someone take a bite and immediately pause, trying to figure out what they were tasting. There's the brioche richness, the cinnamon warmth, that unexpected cream cheese pocket, the custard, and then the sugar rush of the icing and sanding sugars all at once. It's not complicated, but it feels like more than the sum of its parts.

Why This Works for Entertaining

If you're hosting a brunch, this recipe is basically a gift you give yourself the night before. You get to sleep in knowing breakfast is already waiting, you can focus on setting the table or making coffee instead of standing over the stove, and your guests get something that tastes like you spent hours in the kitchen. The best part is that it stays warm for a solid 30 minutes even if people aren't ready to eat right when it comes out of the oven, so there's no stress about timing.

The Magic of Flavored Bread

One year I used cinnamon swirl brioche instead of plain brioche, and honestly, it changed everything. The extra swirls of cinnamon throughout meant every single bite had that spiced warmth, not just the pieces that got coated with the topping. It's a small detail, but it's one of those moves that makes people ask for your recipe. You could even hunt down a bakery that makes chocolate chip brioche if you're feeling adventurous, though then you're in a different dessert territory entirely.

Customizing Without Losing the Soul

I've played around with this enough times to know where you can improvise and where you really can't. The spices, the custard ratio, and the overnight soak are non-negotiable if you want it to taste right. But the filling and toppings are totally fair game. Some mornings I've added a handful of chopped pecans between the bread layers for a subtle crunch, other times I've stirred a tiny bit of bourbon into the icing because why not, and my friend with dairy sensitivities brought plant-based milk and cream cheese alternatives that worked perfectly.

• Pecans or walnuts (½ cup chopped): Scattered between the bread layers, they add a toasty contrast to all that richness.
• Fresh berries on the side: Raspberries or strawberries cut through the sweetness and look beautiful on the plate.
• A dollop of whipped cream instead of just icing: Fresh whipped cream on top of warm casserole is harder to style but impossible to resist.

Pin this

This recipe has become one of those dishes I make when I want to remind myself (and everyone else) that breakfast can be fun. It's festive without being fussy, special without being difficult, and honestly, it tastes just as good on a regular Tuesday as it does on Mardi Gras morning.

Recipe FAQs

→ Can I prepare the dish ahead of time?

Yes, assembling the dish the night before allows the bread to soak up the custard fully, resulting in a tender and flavorful bake.

→ What type of bread works best?

Cinnamon swirl brioche or challah bread provides a soft texture and sweet flavor ideal for soaking up custard.

→ How can I make it dairy-free?

Substitute plant-based milk and cream cheese alternatives to accommodate dairy-free preferences.

→ What gives the topping its festive look?

Colored sanding sugars or sprinkles in purple, green, and gold add a vibrant, celebratory finish after drizzling with icing.

→ Can I add nuts for extra texture?

Adding chopped pecans between bread layers provides a pleasant nutty crunch complementing the soft custard-soaked brioche.