Ham-And-Cheese Croissant Casserole That Breaks Brunch: Buttery Layers, Melty Cheddar, Zero Leftovers

Skip the 27-step brunch routine and make the one dish that always gets demolished. This Ham-And-Cheese Croissant Casserole turns leftover croissants into a golden, custardy, cheesy tower of comfort—like a deli sandwich and a Parisian bakery had a very delicious baby. You whisk, you pour, you bake, and your kitchen smells like a vacation.

It’s bold, rich, and stupid-simple. If your crowd doesn’t ask for seconds, check their pulse.

What Makes This Recipe So Good

This casserole uses torn croissants, which means more craggy edges to soak up creamy custard and crisp in the oven. The combo of salty ham, sharp cheddar, and creamy gruyère hits every corner of your taste buds—savory, tangy, buttery, and a little nutty.

It’s assembled in minutes and bakes hands-off, so you can actually talk to people instead of babysitting a skillet. Plus, you can make it the night before and just slide it into the oven in the morning. That’s the definition of brunch leverage.

Shopping List – Ingredients

• 6 large croissants (preferably day-old; about 16–18 oz total)
• 10 oz diced ham (leftover holiday ham or thick-cut deli ham)
• 1 cup shredded sharp cheddar
• 1 cup shredded gruyère (or Swiss, if that’s what’s in the fridge)
• 8 large eggs
• 2 cups whole milk (or 1 cup milk + 1 cup half-and-half for extra richness)
• 2 tablespoons Dijon mustard
• 1 teaspoon garlic powder
• 1/2 teaspoon onion powder
• 1/2 teaspoon smoked paprika (optional but awesome)
• 1/2 teaspoon black pepper
• 3/4 teaspoon kosher salt
• 2 tablespoons unsalted butter (for greasing and dotting on top)
• 2 green onions, thinly sliced (optional garnish)
• Fresh chives or parsley (optional, for color and freshness)

Let’s Get Cooking – Instructions

1. Prep the pan: Heat oven to 350°F (175°C).

   Generously butter a 9×13-inch baking dish. Yes, butter—it’s a croissant party.

2. Rip the croissants: Tear croissants into large chunks (about 2–3 inches). Spread evenly in the dish so there are layers and air pockets for the custard to sneak into.
3. Add the ham and cheese: Scatter diced ham over the croissants.

   Mix cheddar and gruyère, then sprinkle 3/4 over the top. Save the rest for the finale.

4. Whisk the custard: In a large bowl, whisk eggs, milk, Dijon, garlic powder, onion powder, smoked paprika, pepper, and salt until smooth. The Dijon is the secret handshake—don’t skip it.
5. Pour and press: Pour custard evenly over the croissants.

   Gently press down with your hands or a spatula so the top pieces get a little soak without turning soggy.

6. Optional rest: For best texture, cover and refrigerate 30–60 minutes (or overnight). Short on time? Proceed directly to baking; it’ll still slap.
7. Bake, round one: Dot the top with small bits of the remaining butter.

   Cover with foil and bake for 25 minutes.

8. Cheese finish: Remove foil, sprinkle the remaining cheese, and bake uncovered 15–20 more minutes, until the top is bronzed and the center is just set. A slight jiggle is perfect.
9. Rest and garnish: Let stand 10 minutes before slicing. Top with green onions or chives.

   Serve hot and brace for compliments.

Storage Instructions

• Fridge: Cool completely. Store covered for up to 4 days. Reheat slices in a 325°F oven for 10–15 minutes or microwave in short bursts.
• Freezer: Wrap individual squares tightly in plastic and foil; freeze up to 2 months.

  Thaw overnight in the fridge and reheat in the oven for best texture.

• Make-ahead: Assemble up to 24 hours in advance. Keep covered in the fridge. Add the final cheese layer right before the uncovered bake.

What’s Great About This

• Zero waste upgrade: Stales croissants become the MVP.

  Day-old equals better soak and better structure.

• Big brunch energy: Feeds a crowd without juggling pans. Minimal dishes, maximum applause.
• Balanced richness: The mustard and gruyère cut through the buttery croissants so it’s indulgent without being a food coma trap. Well, not a total one.
• Flexible schedule: Bake now or tomorrow morning.

  It’s forgiving like that, FYI.

Avoid These Mistakes

• Using fresh, fluffy croissants: They’re too soft and collapse. Slightly stale croissants hold shape and texture.
• Over-soaking: Don’t drown the bread. Press gently to hydrate the top, but don’t turn it into soup.
• Skipping the salt: Ham is salty, but the custard still needs seasoning.

  Otherwise the whole dish tastes flat.

• Baking dry: If your oven runs hot, tent with foil sooner and check early. You want custardy, not crouton casserole.
• Cheese monotony: Only cheddar can feel one-note. Blend cheeses for depth and meltability.

Recipe Variations

• Spinach & Mushroom: Sauté 8 oz sliced mushrooms and 3 cups baby spinach until moisture cooks off.

  Layer with ham or go vegetarian.

• Jalapeño Popper: Add 4 oz softened cream cheese in dollops, 1–2 sliced jalapeños, and swap cheddar for pepper jack. A little chaos, a lot of flavor.
• Everything Bagel Vibes: Sprinkle 1–2 tablespoons everything bagel seasoning over the top before baking. Serve with a dollop of sour cream.
• French-Onion Twist: Caramelize 2 large onions, splash with a little sherry or white wine, and fold in with gruyère and thyme.
• Herb & Lemon: Add 1 tablespoon chopped fresh thyme and zest of 1/2 lemon to the custard for a bright finish.
• Turkey Breakfast Club: Swap ham for turkey, add cooked crumbled bacon, and toss in cherry tomato halves post-bake for a fresh pop.

FAQ

Can I use regular bread instead of croissants?

Yes, but expect a different texture.

Use sturdy bread like brioche or challah, lightly toasted. You’ll miss some buttery layers, but the custard and cheese still deliver.

Is there a lighter version?

Use 2% milk, reduce cheese by 25%, and swap half the ham for sautéed veggies. It’s still satisfying, just less decadent.

IMO, keep the Dijon for flavor impact.

Do I have to rest it overnight?

No. Resting improves soak and structure, but a quick 10-minute press and straight-to-oven method still works. If you can spare 30–60 minutes, it’s the sweet spot.

How do I know it’s done?

The edges should be golden, the top puffed, and the center slightly jiggly but not liquid.

A thermometer in the middle should read about 165°F.

What cheeses melt best here?

Gruyère and cheddar are the power duo. Other great options: fontina, Swiss, or Monterey Jack. Avoid super-aged cheeses that don’t melt smoothly.

Can I make this gluten-free?

Use gluten-free croissants or sturdy GF bread and confirm your ham and mustard are certified GF.

Everything else plays nice.

Could I assemble in a skillet instead of a baking dish?

Absolutely. A 12-inch oven-safe skillet works. Grease well, monitor bake time (it may cook a bit faster), and prepare for dramatic, puffy edges.

What should I serve with it?

Fresh fruit, a crisp arugula salad with lemon vinaigrette, and maybe roasted asparagus.

Add hot sauce on the table for the spice crowd.

Can I use bacon or sausage instead of ham?

Yes. Cook and drain well first to avoid greasy casserole. Aim for about 10–12 oz cooked meat total.

Why is my casserole soggy?

Likely too much liquid, super-fresh croissants, or underbaking.

Next time, use day-old croissants, measure milk accurately, and bake until set with a light jiggle.

The Bottom Line

This Ham-And-Cheese Croissant Casserole is the brunch flex that actually makes your life easier. It’s buttery, cheesy, and reliably crowd-pleasing with minimal effort. Make it once and it’ll be your new “oh, I’ve got just the thing” move.

Weekend or weekday, it performs. Prepare for clean plates and zero leftovers—don’t say I didn’t warn you.