Ham and Cheese Croissant Breakfast Casserole

This Ham and Cheese Croissant Breakfast Casserole is the kind of recipe that makes people think you’ve been up since dawn doing something impressive. Spoiler: you haven’t. I’m Linda Sandra — a Charleston home cook who believes brunch should be cozy, gorgeous, and secretly easy.

This overnight breakfast casserole is built on flaky croissants soaked in a savory egg custard, tucked with layers of ham and melty Swiss or Gruyere. It goes together in minutes and bakes up golden, bubbly, and absolutely show-stopping.

I first made this for a lazy Sunday when I had leftover ham from a holiday dinner and a bag of croissants just sitting there, daring me to do something fun. One pan later, the whole family was gathered around the table asking for seconds.

Little Snapshot: What This Recipe Delivers

This Ham and Cheese Croissant Breakfast Casserole layers buttery torn croissants with deli ham and shredded Swiss or Gruyere, all soaked in a Dijon-spiked egg custard.

It preps in about 10 minutes, chills overnight (or just 30 minutes), and bakes in under 35 minutes. It’s a crowd-pleasing weekend brunch bake that tastes deeply savory, rich, and a little fancy — with almost zero effort.

Nutritional Peek

Here’s an approximate nutritional breakdown per serving of this ham cheese breakfast bake (based on 8 servings).

Nutrient	Amount Per Serving
Calories	~340 kcal
Protein	~18 g
Carbohydrates	~22 g
Fat	~20 g
Fiber	~1 g
Sugar	~4 g

Ingredients

For this overnight breakfast casserole, you’ll want your croissants to be medium-sized — bakery or grocery store both work great. The wet ingredients (eggs, half and half, and Dijon mustard) come together in one bowl for a silky custard.

For the fillings, deli ham and shredded Swiss or Gruyere are your stars. A pinch of salt and a dusting of powdered sugar to finish round everything out beautifully.

Amount	Ingredient
6–8 medium	Croissants
4 large	Eggs
1 cup	Half and half or whole milk
1 1/2 tablespoon	Dijon mustard
1 pinch	Salt
8 ounces	Deli or leftover ham (about 6 thin slices)
6 ounces	Shredded Swiss or Gruyere cheese
To taste	Powdered sugar (for finishing)

Tools You’ll Actually Use

• 9×6 deep baking dish (or 9×11 baking dish)
• Cooking spray
• Small mixing bowl
• Whisk
• Aluminum foil
• Fine mesh sieve or small strainer (for powdered sugar)

Step-by-Step Instructions for Ham and Cheese Croissant Breakfast Casserole

Ready to make your new favorite ham cheese breakfast bake? Here’s exactly how to do it, step by step.

1. Prep your pan. Lightly coat a 9×6 deep baking dish with cooking spray. A 9×11 baking dish also works great if you want a flatter, wider casserole.
2. Layer the croissants and ham. Tear the croissants in half and arrange them in the prepared pan. Cut your ham slices into thirds and nestle the pieces in and around the croissants. Sprinkle the shredded Swiss or Gruyere evenly on top — don’t be shy with the cheese.
3. Make the custard. In a small bowl, whisk together the 4 large eggs, 1 cup of half and half, 1 1/2 tablespoon Dijon mustard, and a pinch of salt until smooth and well combined.
4. Pour and chill. Pour the custard evenly over the croissants, making sure everything gets a good soak. Cover with foil and refrigerate for at least 30 minutes — or overnight for best results.
5. Bake covered. When ready to bake, preheat your oven to 350 degrees F. Place the foil-covered casserole dish in the oven and bake for 20 minutes.
6. Bake uncovered until golden. Remove the foil and continue baking for another 10 to 15 minutes, until the top is golden and the casserole is hot and bubbly. Your kitchen should smell absolutely heavenly at this point.
7. Rest and finish. Remove the casserole from the oven and let it rest for 5 minutes. Dust generously with powdered sugar just before serving for that gorgeous finishing touch.

Pro Tips for the Best Weekend Brunch

This weekend brunch recipe is pretty forgiving, but a few small habits will take it from good to absolutely unforgettable.

Don’t skip the overnight chill. If you have time, letting the casserole sit overnight in the fridge is a game-changer. The croissants absorb the custard deeply, and the texture becomes incredibly rich and custardy all the way through.

Use room-temperature eggs. Cold eggs straight from the fridge can cause the custard to set unevenly. Give them 15 minutes on the counter before whisking.

Press the croissants gently. After pouring the custard over, give the croissants a gentle press down with the back of a spoon. This helps them absorb more of that savory, Dijon-kissed goodness.

Let it rest before serving. Those 5 minutes of rest aren’t just formality — they let the custard finish setting so your slices hold together beautifully.

Quick Fixes for Ham and Cheese Croissant Breakfast Casserole

Top is browning too fast: If the croissants are getting too golden before the center is set, loosely tent the dish with foil for the last 10 minutes of baking. The center will catch up without burning the top.

Casserole is watery in the center: This usually means it needed a few more minutes in the oven. Pop it back in for 5–8 more minutes, uncovered, and check again. An internal temperature of around 160 degrees F means you’re good to go.

Croissants are dry on top: This can happen if the custard didn’t fully cover all the pieces. Before baking, press those top pieces down into the custard and spoon a little extra over any dry spots.

Casserole won’t release cleanly: Make sure your baking dish is well-coated with cooking spray before you build the layers. If you forgot, let it cool for an extra few minutes — it’ll firm up and release more easily.

Variations and Adaptations

This ham cheese breakfast bake is a great base recipe that’s easy to riff on depending on what you have in the fridge or what your crew is craving.

• Dairy-free: Swap the half and half for full-fat oat milk or coconut cream, and use a dairy-free shredded cheese. The texture will be slightly lighter but still delicious.
• Gluten-free: Use your favorite certified gluten-free croissants (they do exist!) or substitute with gluten-free bread rolls for a similar custardy texture.
• Swap the protein: Not a ham person? Try cooked crumbled breakfast sausage, crispy bacon, or even smoked turkey for a lighter spin on the ham cheese breakfast bake.
• Add veggies: Fold in some sauteed spinach, roasted red peppers, or caramelized onions between the croissant layers for extra color and flavor.
• Change up the cheese: Fontina, sharp cheddar, or Gouda all melt beautifully and make great swaps for the Swiss or Gruyere.

Serving, Storage, and Reheating

This Ham and Cheese Croissant Breakfast Casserole is stunning straight from the oven. Pair it with a fresh fruit salad, a simple green salad, or a big pot of coffee for the perfect weekend brunch spread. A light dusting of powdered sugar right before serving makes it look absolutely bakery-worthy.

If you somehow manage not to eat the whole thing in one sitting, store leftovers in an airtight container in the refrigerator for up to 3 days. Cover the baking dish tightly with plastic wrap or foil if storing in the original pan.

To reheat, place individual portions in a 325 degree F oven for about 10–12 minutes until warmed through. You can also microwave single slices for 60–90 seconds, though the oven method keeps the croissants crispier and more enjoyable.

No-Waste Kitchen Magic

Have leftover casserole that’s past its prime for straight serving? Chop it up and fold it into a scrambled egg situation for a whole new breakfast the next morning.

Stale croissants work even better in this recipe than fresh ones — they soak up the custard more readily without getting soggy. So if you’ve got day-old croissants sitting around, this is their moment to shine.

Leftover ham from a holiday roast is absolutely perfect here. This is a wonderful recipe to bookmark for the day after Easter, Christmas, or any time you’ve got a ham in the fridge that needs a delicious purpose.

Love make-ahead brunch ideas? Our meal prep buffalo chicken bowls are another great recipe to have ready in the fridge for the week ahead.

FAQs About Ham and Cheese Croissant Breakfast Casserole

Final Thoughts

So there you go — a Ham and Cheese Croissant Breakfast Casserole that feels fancy but is secretly one of the easiest things you’ll ever pull out of your oven.

I’d love to see your version of this recipe! Drop a comment below with your photos or your favorite twists on this ham cheese breakfast bake. Did you use Gruyere? Sneak in some spinach? Add bacon instead of ham? Tell me everything — I love seeing how you make it your own.

Whether this is your first time making an overnight breakfast casserole or you’re a seasoned brunch host, this recipe is going to become a regular in your kitchen. Warm, cheesy, golden, and full of cozy weekend vibes — exactly how brunch should feel.

I’m Linda Sandra — a Charleston home chef and comfort-food daydreamer. Around here, cooking’s not about perfection — it’s about cozy vibes, creative twists, and food that feels like love.