Overnight Croissant Breakfast Dish

This overnight croissant breakfast casserole transforms buttery croissants into a decadent morning treat that's prepped the night before. As someone who hosts frequent family brunches, I've found this recipe to be my secret weapon for enjoying time with guests instead of being stuck in the kitchen.

I first created this casserole when my in-laws came for a holiday weekend. The delighted expressions when they took their first bites convinced me this would become our family's special occasion breakfast tradition.

Ingredients

• Six large croissants: Torn into pieces provides the buttery base and creates perfect nooks for the egg mixture to soak into
• One pound breakfast sausage: Adds hearty protein and savory depth, look for sage flavored for extra dimension
• Two cups shredded cheddar cheese: Creates those wonderful stretchy cheese pulls, opt for medium or sharp based on your preference
• Six large eggs: Form the custard that binds everything together, use room temperature for the smoothest mixture
• Two cups milk: Creates the perfect creamy texture, whole milk provides the richest result
• Dry mustard: Brings subtle tanginess that balances the richness
• Salt and pepper: Essential for bringing all the flavors together

Step-by-Step Instructions

Prepare the Baking Dish:

Thoroughly grease your 9×13 baking dish with butter making sure to get the corners. Tear or cut croissants into approximately 2 inch pieces and arrange them evenly in the dish. The croissants should fill the dish but not be tightly packed, allowing room for the egg mixture to soak in.

Add Sausage and Cheese:

Brown the breakfast sausage in a skillet over medium heat until fully cooked, breaking it into small crumbles as it cooks. Drain excess fat on paper towels before sprinkling the sausage evenly over the croissant pieces. Follow with an even layer of shredded cheese, distributing it so every serving will have plenty of cheesy goodness.

Make the Egg Mixture:

In a large bowl, whisk the eggs until completely combined and slightly frothy, about 30 seconds of vigorous whisking. Add the milk, dry mustard, salt, and pepper, continuing to whisk until everything is fully incorporated. The dry mustard will want to clump, so be sure to whisk thoroughly until the mixture is smooth and uniform in color.

Assemble the Casserole:

Slowly pour the egg mixture over the layers in the baking dish, making sure to distribute it evenly. Using the back of a spoon, gently press down on the croissant pieces to help them absorb the liquid. The croissants will initially float but will gradually soak up the custard mixture.

Refrigerate:

Cover the dish tightly with plastic wrap and refrigerate for at least 2 hours but preferably overnight. This resting period is crucial as it allows the croissants to fully absorb the egg mixture, resulting in a pudding-like texture rather than dry bread with scrambled eggs.

Bake to Golden Perfection:

Preheat your oven to 350°F and remove the casserole from the refrigerator to take the chill off while the oven heats. Bake uncovered for 40 to 45 minutes until the top is beautifully golden brown and the center is set. The casserole should have a slight jiggle but not appear wet or runny.

Serve Warm:

Allow the casserole to rest for 5 to 10 minutes before cutting it into portions. This brief resting period makes cutting cleaner and lets the flavors settle. Serve while still warm when the cheese is at its melty best.

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My absolute favorite part of this casserole is how the edges of the croissants that peek out from the custard become golden and crispy while the interior stays soft and custardy. This textural contrast reminds me of the bread puddings my grandmother made though she would never have imagined using croissants.

Make It Your Own

This breakfast casserole welcomes endless variations to suit your taste or use what you have on hand. Try swapping the sausage for crispy bacon or diced ham. Vegetarians can substitute sautéed mushrooms, spinach, and bell peppers for a garden fresh version. The cheese can be changed to Swiss, Gruyère, or pepper jack depending on your flavor preference. For a touch of sweetness, add a diced apple or a sprinkle of fresh berries just before baking.

Serving Suggestions

While this casserole is certainly satisfying on its own, I love to create a complete brunch spread around it. A simple green salad with vinaigrette provides a refreshing contrast to the richness. Fresh fruit, especially citrus or berries, cuts through the savory flavors beautifully. For special occasions, offer mimosas or a spicy Bloody Mary station alongside a carafe of fresh coffee. A small dish of maple syrup on the table lets guests add a touch of sweetness if desired.

Storage and Reheating

The beauty of this casserole extends to its leftover potential. Store any remaining portions in an airtight container in the refrigerator where they will keep for up to three days. To reheat single servings, microwave for 1 to 2 minutes until warmed through. For a crisper texture, reheat in a 325°F oven for about 15 minutes. This casserole also freezes exceptionally well. Cut cooled leftovers into individual portions, wrap tightly in plastic, and freeze for up to two months. Thaw overnight in the refrigerator before reheating.

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Frequently Asked Questions

→ Can I use a different type of bread instead of croissants?

Yes, you can substitute croissants with brioche, challah, or even sliced sandwich bread for a similar texture and flavor.

→ Can I make this dish without sausage?

Absolutely! You can omit sausage or replace it with other proteins like cooked bacon, ham, or a vegetarian alternative.

→ Can I freeze the prepared casserole?

Yes, you can freeze it assembled but unbaked. Thaw it overnight in the fridge before baking for the best results.

→ How can I ensure the egg mixture soaks into the croissants?

Press down gently on the layers with a spatula after pouring the egg mixture to help it absorb evenly.

→ What vegetables can I add to this dish?

Diced bell peppers, spinach, mushrooms, or onions make great additions to enhance the flavor and nutrition.