Buttery Breakfast Casserole Recipe • 5★

Updated February 2, 2025

Andrew Scrivani for The New York Times

The word “buttery” in the title refers to croissants, which make an especially rich foundation for this golden-topped baked breakfast classic. Toasting the croissants before building the casserole adds caramelized notes that can stand up to the bits of browned sausage, sage and melted Gruyère strewn throughout. Make this the night before a special breakfast or brunch, then pop it in the oven an hour before you plan to serve it.

Featured in: A Breakfast Casserole That’s Comfort Food at Sunrise

SaveLog in or sign up to save this recipe.

GiveSubscriber benefit: Give recipes to anyoneAs a subscriber, you have 10 gift recipes to give each month. Anyone can view them - even nonsubscribers. Learn more.SubscribeLog In

Subscriber benefit: Give recipes to anyone

As a subscriber, you have 10 gift recipes to give each month. Anyone can view them - even nonsubscribers. Learn more.

Share this recipeCopy linkEmailPinterestFacebookXWhatsAppReddit

Print this recipeInclude recipe photoPrint RecipeLog in or sign up to print this recipe.

1 pound croissants (about 5 to 7), split in half lengthwise

1 tablespoon extra-virgin olive oil, more for baking dish

1 bunch scallions (6 to 7), white and light green parts thinly sliced, greens reserved

¾ pound sweet Italian sausage, casings removed

2 teaspoons finely chopped fresh sage

3 cups whole milk

1 cup heavy cream

8 ounces Gruyère, grated (2 cups)

1 ¼ teaspoons kosher salt

1 teaspoon black pepper

Step 1Heat oven to 500 degrees. Spread croissants on a large baking sheet and toast, cut side up, until golden brown, 5 to 10 minutes (watch carefully to see that they do not burn). Let cool, then tear into large bite-size pieces.

Heat oven to 500 degrees. Spread croissants on a large baking sheet and toast, cut side up, until golden brown, 5 to 10 minutes (watch carefully to see that they do not burn). Let cool, then tear into large bite-size pieces.

Step 2In a medium skillet over medium-high heat, warm the olive oil. Add sliced scallions and sausage meat; cook, breaking up meat with a fork, until mixture is well browned, about 5 minutes. Stir in sage, and remove from heat.

In a medium skillet over medium-high heat, warm the olive oil. Add sliced scallions and sausage meat; cook, breaking up meat with a fork, until mixture is well browned, about 5 minutes. Stir in sage, and remove from heat.

Step 3In a large bowl, toss together croissants and sausage mixture. In a separate bowl, whisk together eggs, milk, cream, 1 ½ cups cheese, salt and pepper.

In a large bowl, toss together croissants and sausage mixture. In a separate bowl, whisk together eggs, milk, cream, 1 ½ cups cheese, salt and pepper.

Step 4Lightly oil a 9- x 13-inch baking dish. Turn croissant mixture into pan, spreading it out evenly over the bottom. Pour custard into pan, pressing croissants down gently to help absorb the liquid. Cover pan with plastic wrap and refrigerate at least 4 hours or overnight.

Lightly oil a 9- x 13-inch baking dish. Turn croissant mixture into pan, spreading it out evenly over the bottom. Pour custard into pan, pressing croissants down gently to help absorb the liquid. Cover pan with plastic wrap and refrigerate at least 4 hours or overnight.

Step 5When you’re ready to bake the casserole, heat oven to 350 degrees. Scatter the remaining grated cheese over the top of the casserole. Transfer to oven and bake until casserole is golden brown and firm to the touch, 45 minutes. Let stand 10 minutes. Garnish with sliced scallion tops before serving.

When you’re ready to bake the casserole, heat oven to 350 degrees. Scatter the remaining grated cheese over the top of the casserole. Transfer to oven and bake until casserole is golden brown and firm to the touch, 45 minutes. Let stand 10 minutes. Garnish with sliced scallion tops before serving.

Goodness! Did all you complainers bother to do the math? It's meant to be 8-10 servings. Let's go crazy and call it FIVE instead. What do you end up with in terms of calorically relevant food per person? About 1 croissant, about 3 g oil, about 2.5 oz sausage, approx an egg and a half, a good 1/2 cup of milk, 1.6 oz heavy cream, and 1.6 oz Gruyere. Health food to wolf down on my way to the squat rack? No. A delight to share with my family on our favorite morning of the year? To be sure.

This is the bomb !!! In every good sense I can think of !!!! People need to get over themselves and quit being such naughty children ! If you don't like the list of ingredients, that's your problem. Don't make it and don't criticize it. Life is too short to not savor ever single bite of deliciousness out there. And no, I do NOT weigh over 200 pounds. I believe moderation is important, including moderation....:-)

I did a practice run with sweet sausage and Swiss cheese, It is wonderful. I think the possibilities are endless. Quiche Lorraine style with bacon onion and Swiss. Mushrooms and breakfast sausage. Ham and Broccoli with cheddar, Veggie style with onion, mushroom, green pepper and fresh tomato. Thank You Melisa Clark - I Love You :)

I made this for Mother’s Day Brunch in 2026 and it was delicious and a huge hit with family. I added an extra egg as many suggested, but did not reduce the amount of milk, and both worked out great. Very easy to make ahead the night before.

Terrific! The costco had some croissant loaf bread and we cubed that up and toasted it. About 1.5 slices is equal to one croissant. This recipe made me a believer in the judicious use of Gruyère cheese. This is the literal bomb! Thanks!