Croissant breakfast casserole turns bakery croissants, savory ham, nutty Gruyere, and a simple egg custard into a brunch centerpiece with very little morning work. The croissants soak overnight, so you can assemble the dish before bed and bake it when guests arrive. After a covered start and an uncovered finish, the center is tender and set while the exposed croissant edges turn lightly golden. Serve this rich, make-ahead casserole warm with a dusting of confectioners’ sugar and jam.
What makes this croissant breakfast casserole special
This is a savory breakfast bake with a gentle Monte Cristo-inspired finish. Croissants bring buttery layers and enough structure to hold the custard, ham adds salt and substance, and Gruyere melts into the gaps. The egg mixture is deliberately simple: half-and-half creates a creamy set, Dijon adds a quiet sharp note, and black pepper keeps the flavor balanced.
Why the overnight soak works
The rest is more than a convenience. It gives the custard time to move through the torn croissants instead of leaving dry centers. Day-old croissants are especially useful because they absorb the eggs without collapsing as quickly. If you only have fresh croissants, let the assembled dish rest for the full hour and press the pieces down once or twice.
Ingredients you will need
- Croissants: Use about 6 large or 12 mini bakery croissants, torn into large pieces.
- Ham and Gruyere cheese: Four slices of deli ham and 1 cup grated Gruyere cheese create the savory layers. Swiss is an easy substitute.
- Custard: Six eggs, 2 cups half-and-half, 2 teaspoons Dijon mustard, salt, and ground black pepper.
- Dish: A greased 9-by-13-inch baking dish and nonstick cooking spray give the casserole room to bake evenly.
How to make it
Build the layers
- Spray a 9-by-13-inch baking dish with nonstick spray.
- Scatter the torn croissant pieces in the baking dish.
- Wind the ham strips around the croissants and sprinkle the grated Gruyere over the top.
Make and add the custard
- Whisk the eggs, half-and-half, Dijon mustard, salt, and pepper in a medium bowl.
- Pour the egg mixture over the casserole. Press the croissants down gently so they soak up the custard and some cheese settles between the pieces.
- Cover and refrigerate for at least 1 hour and up to 12 hours, pressing the croissants down occasionally so they are fully soaked.
Bake until the center is set
- Take the casserole from the refrigerator 15 minutes before baking and heat the oven to 350°F.
- Loosely cover with foil and bake for 20 minutes.
- Remove the foil and bake for 15 to 20 minutes more, until the center is cooked through. Re-cover if the croissants brown too quickly.
Serving ideas
Serve warm with confectioners’ sugar and jam if desired. Serve slices warm with confectioners’ sugar and jam for a sweet-savory contrast. Fresh fruit, bacon, or breakfast sausage can round out a brunch spread, but the casserole is substantial enough to stand on its own. Cut through the center before serving: the custard should look set rather than liquid, and the croissant pieces should be tender without being soggy.
Tips for the best texture
Keep the croissant pieces fairly large so they retain their buttery layers. Do not pack them down before pouring in the custard; the liquid needs spaces to travel. Press them gently after the pour instead. For the most even bake, let a cold overnight casserole sit out for 15 minutes while the oven heats, and loosely cover it so steam can escape around the edges.
Optional variation
For an optional cheese variation, replace the Gruyere with the same amount of grated Swiss, Fontina, or Jarlsberg. Keep the ham and custard quantities the same so the casserole’s moisture and baking time stay consistent.
Storage and reheating
Cool leftovers promptly, cover them, and refrigerate for up to 3 days. Reheat individual portions in the microwave until hot, or warm a larger portion covered in a 325°F oven. Because the croissants continue to soften in storage, gentle oven reheating helps the edges regain some texture without drying the custard.
Planning a brunch around it
This casserole is a practical choice when breakfast needs to serve a group from one pan. Assemble it after dinner, keep the baking dish covered and chilled, then set out fruit and drinks while it bakes. The one-hour soak is the minimum, but the overnight option also makes the timing predictable for a holiday morning or a late weekend breakfast.
Search answers for croissant breakfast casserole
Can I assemble it the night before?
Yes. Cover the assembled casserole and refrigerate it for up to 12 hours, pressing the croissants down occasionally so they soak evenly.
What cheese can replace Gruyere?
Use grated Swiss, Fontina, or Jarlsberg in the same quantity. Each melts well and keeps the casserole savory.
How do I know it is done?
The center should be cooked through and set when the dish is gently nudged. The top should be lightly golden, not wet, while the croissants remain tender.
FAQ: croissant breakfast casserole questions
A make-ahead brunch centerpiece
With a one-hour minimum soak and a straightforward bake, this croissant breakfast casserole fits both relaxed weekends and holiday brunches. Assemble it ahead, watch the center rather than the clock, and serve it while the croissants are warm and the cheese is melted.
Croissant Breakfast Casserole with Ham and Gruyere
Adjust the serving amount to scale the ingredient list. Written quantities in the steps refer to the original recipe; adjust them in the same proportion. Timing may vary with batch size.
Ingredients
Ingredients
- 1 pound bakery croissants about 6 large or 12 mini, torn into 3-inch pieces
- 4 slices deli ham cut into 2-inch strips
- 1 cup gruyere cheese grated; Swiss may be substituted
- 6 large eggs beaten
- 2 cups half-and-half or 1 cup milk plus 1 cup heavy cream
- 2 teaspoons Dijon mustard
- 1/2 teaspoon salt
- 1/4 teaspoon ground black pepper
- nonstick cooking spray for the baking dish
Instructions
Instructions
- Spray a 9-by-13-inch baking dish with nonstick spray.
- Scatter the torn croissant pieces in the baking dish.
- Wind the ham strips around the croissants and sprinkle the grated Gruyere over the top.
- Whisk the eggs, half-and-half, Dijon mustard, salt, and pepper in a medium bowl.
- Pour the egg mixture over the casserole. Press the croissants down gently so they soak up the custard and some cheese settles between the pieces.
- Cover and refrigerate for at least 1 hour and up to 12 hours, pressing the croissants down occasionally so they are fully soaked.
- Take the casserole from the refrigerator 15 minutes before baking and heat the oven to 350°F.
- Loosely cover with foil and bake for 20 minutes. Remove the foil and bake for 15 to 20 minutes more, until the center is cooked through. Re-cover if the croissants brown too quickly.
- Serve warm with confectioners' sugar and jam if desired.
