Overnight Croissant Breakfast Casserole – Buttery, Savory, and Make-Ahead
This Overnight Croissant Breakfast Casserole combines flaky croissants, eggs, cheese, and bacon or sausage in a rich, custardy bake. Perfect for brunch or holidays — and it’s all prepped the night before.
Ingredients
-
6 large croissants, sliced
-
6 large eggs
-
1 cup whole milk
-
1 cup heavy cream
-
1½ cups shredded cheddar or Swiss cheese
-
1 cup cooked crumbled bacon or sausage
-
1 tsp Dijon mustard
-
½ tsp salt
-
¼ tsp black pepper
-
Optional: scallions, sautéed veggies, or herbs
Instructions
-
Grease a 9×13-inch baking dish. Layer croissant pieces on the bottom.
-
Sprinkle with meat, cheese, and optional vegetables.
-
In a bowl, whisk eggs, milk, cream, mustard, salt, and pepper.
-
Pour over croissant mixture and press gently to soak.
-
Cover and refrigerate overnight (or at least 6 hours).
-
Remove from fridge 30 minutes before baking.
-
Bake at 350°F, covered for 30 mins, then uncovered for 15–20 mins until set and golden.
-
Cool 10 minutes before serving.
Notes
Use day-old croissants for best texture. Swap in vegetables or different cheeses. Freezes well after baking.