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Made 2 of these for a XMAS work brunch. One with ham and the other with mushrooms. Even the “NO-ONION” eaters loved it!!!
Kate
This Croissant Breakfast Casserole Is Blowing My Mind
So you love brunch, too?
And you stand in support of Swiss and Gruyere cheese, brown sugar ham, caramelized onions, and spinach baked into creamy eggs and topped with a crispy golden croissant topping?
Okay, yes. Welcome. You and I are on the same team.
You will not even believe how easy this croissant egg bake is. We are just layering a bunch of delicious things in a casserole dish, popping it in the oven, and setting it out on the table. That’s it. It’s perfect for Christmas morning, and Easter brunch, or just on a normal Saturday morning.
Will you be the belle of the brunch ball? Yes.
Are you cool as a cucumber for how easy this whole thing was? Double yes.
All you do is win. Eggs, cheese, ham, and croissant brunchy style.
I love brunch! Get all my favorite brunch recipes here.
Watch How To Make This Egg Bake
Ingredients You Need
Here’s a list of what you’ll need on hand for this recipe. It’s short, simple, and easy to find!
- An onion (we’re going to caramelize it, oh yes!)
- Ham
- Spinach
- Eggs
- Cheese
- Croissants
How To Make This Brunch Bake
1
Caramelize Your Onions In a Large Skillet.
Low and slow, friends. We want to see almost-jammy onions that are a reeeally deep, rich, golden brown.
2
Combine With Ham and Spinach.
Toss your onions with some browned ham and spinach in a 13-inch baking dish.
3
Layer Your Casserole.
Sprinkle that cheese in there like it’s your job, pour the egg mixture in from a bowl, and top with your torn-up croissants, then more cheese.
4
Bake and Serve!
Wrap in foil, bake that guy up, and pull it out of the oven juuuust before it’s fully cooked. I am kind of sensitive about overcooked eggs and I really recommend undercooking slightly and letting this one finish gently by just resting on the counter for a few minutes.
Frequently Asked Questions
Regular croissants are just fine! A pack of four standard croissants should be enough.
I would sub in some mushrooms for the ham!
Mozzarella, gruyere, or white cheddar cheese work wonderfully!
Sure would! Just cook it fully, and then use it in the casserole exactly as you would add the ham.
I mean, I LOVE the caramelized onions in this, but this would still work without them.
All the usual brunch suspects! Fresh fruit, maybe a green salad, some sweet pastries, coffee and juice – perfection!
Yep! Do steps 1 and 2 the night before, and then everything else day-of. The only part I would not recommend doing ahead of time is letting the croissant pieces soak in the egg mixture overnight.
Covered and in the fridge is best. It will keep for 3-4 days. You can reheat the whole thing in the oven or individual slices in the microwave.
Egg and Croissant Brunch Bake
- Total Time: 1 hour
- Yield: 9–12 1x
Description
The BEST Croissant Brunch Bake! Cheese, brown sugar ham, caramelized onions, and spinach baked into creamy eggs and topped with a crispy golden croissant topping. YUM.
Ingredients
- 2 tablespoons olive oil
- 1 large yellow onion, sliced thinly
- 2 1/2 cups diced ham
- 2–3 ounces fresh baby spinach
- 1 cup shredded cheese (I used a Swiss/Gruyere mix)
- 12 eggs
- 1/2 cup milk
- 1 tablespoon Dijon mustard
- 1 teaspoon salt
- pepper to taste
- 5–6 mini croissants, torn into small pieces (or 3–4 large size)
Instructions
- Caramelize the Onions: Heat the olive oil over medium-low heat in a large heavy pan. Add the onions and cook, stirring occasionally, for about 30 minutes. End goal: almost-jammy onions that are a reeeally deep, rich, golden brown. (Also, you probably smell like deliciously caramelizey onions now! New signature perfume?)
- Ham and Spinach: Toss the ham in a skillet with a quick drizzle of olive oil. Pan-fry until the edges are kind of browned and some of the fat is rendered. Throw in your spinach. Stir to wilt the spinach. Remove from heat.
- Eggs: Whisk eggs with the milk, dijon, salt, and pepper.
- Layer: Preheat the oven to 350 degrees. Grease a 9×13 baking dish. Layer the ham, spinach, and onions on the bottom. Sprinkle with half of the cheese. Pour eggs over. Arrange croissant pieces on top. Finish with remaining cheese.
- Bake: Cover with foil. Bake for 30 minutes, depending on oven and pan size. Remove foil and bake for another 5-10 minutes. You don’t want to overcook the eggs (gross) but the middle should be almost completely firm when you give the pan a quick jiggle test. You’ll also notice the whole thing will be just starting to puff up a bit. Slice, serve, and brunch forward!
Notes
Make Ahead: Yes, you can make this ahead of time! I like to do steps 1 and 2 the night before, and then everything else day-of. The only part I would not recommend doing ahead of time is letting the croissant pieces soak in the egg mixture overnight.
Pan Size: My favorite version of this was in a casserole dish that was slightly smaller than 9×13 – the pieces were a little thicker and it took closer to 40 minutes to bake.
- Prep Time: 20 minutes
- Cook Time: 40 minutes
- Category: Breakfast
- Method: Bake
- Cuisine: American
Keywords: egg and croissant brunch bake, brunch bake, egg bake
One More Thing!
This recipe is part of our yummy spinach recipes page. Check it out!
Made this for Mother’s Day brunch and received many compliments & requests for a second helping. I had a guest with a spinach allergy so added mushrooms in lieu of that and added rosemary as well. Will definitely be making this again!
Made this today for Easter breakfast. I served bacon on the side since I didn’t have ham. Turned out excellent, the hint of Dijon added a great flavor.
Does the quality of the croissant matter in this recipe? Would Costco or TJ ones work just as well as my favorite bakery’s croissant? Thanks!
Yes, we use those all the time!
I just used deli ham and it turned out great, but would be a perfect way to use up leftovers from a holiday.
My family wasn’t the biggest fan of the mustard/carmelized onion & egg combo so I’ll probably make again without the onions and probably cheddar cheese!
Could I prebake this and then freeze? If I’m batch cooking for my family?
Yep!
Silly question: which level of fat for the milk do you recommend? Thank you!
Whole milk!
This was amazing! I brought it for a family brunch and a self proclaimed egg bake hater said it was good! I used Gouda cheese and bacon instead of ham. I received so many compliments. Definitely looking forward to riffing on this base recipe.
Sounds delicious! Can I somehow use lactose-free products for this or does it need the milk to bind well together?
This recipe was delicious. I used bacon instead of ham and mozzarella for the cheese. Also used jalapeño croissants because that’s what I had. Just goes to show it is really versatile and super yummy!
The best egg casserole I’ve ever made. And I’ve made a lot of different ones. I used the cheese and mini croissants from Aldi’s as suggested. I did add 1/4 tsp nutmeg, and I swapped out the ham for cooked Jimmy Dean hot breakfast sausage for hubby’s preference.
I made this for Mother’s Day just last weekend and it was a hit – from my 86 year old mother to my 10 year old daughter! I made a 1/2 batch since there were only 3 of us and it was perfect – very easy to put together. Definitely a keeper!
Made this with sausage for Easter. I don’t even like egg casseroles and this was delicious.
Best egg bake I’ve ever had!
This recipe rules. Restaurant quality!
My all time favorite egg bake! 3 pans on the way with my husband to a men’s breakfast Bible study.
Very tasty! Was a hit even with my husband who “hates egg casseroles”. I have been determined to find one that would work because egg casseroles make my life a lot easier.
My 20 month old liked it as well, I’ll try it out on the 4 year old tomorrow.
I doubled the caramelized onions and added a bit more cheese but otherwise made it as written! Yum!
Do you think you could freeze this?
I think you could!
Simple decadent! My family loved this casserole for brunch! This will be on repeat!
Do you bake the crescents before you add to the casserole?
Nope, they bake in the casserole itself!
My MIL made this for Christmas and it was a 10/10. Love me some ham for breakfast.
Hi Lindsay,
I’d like to make your Egg & Croissant brunch bake in the 2x size for 18-22 servings but need some direction on what size baking dish to use & how long to bake it for.
All of the instructions for each size say a 9×13 dish & to bake for 30 mins
Thanks
Love this delicious recipe and so did my family when I made it for brunch! I love that I can prep a lot ahead and pop in the oven in the am!
Yum
I’m hoping to try this recipe for an event happening at the school I work at. However, Aldi didn’t have the ham you suggested using, so I got the plain ham instead. Do you suggest adding anything to help with the missing flavor? Since the event is also fairly early, would it work to rewarm it up morning of, or does it still work cold?
My 5 guests rated your breakfast casserole 5 stars. So easy to make. I served it with a salad. Merci.