If you’ve been chasing the feeling of a toasted everything bagel with cream cheese but you need to feed 6–8 people before the school bus comes, this everything bagel casserole is it.
Cubed plain bagels soak up an eggy custard, get loaded with chicken sausage, baby spinach, and cherry tomatoes, then bake up with molten pockets of cream cheese and a crunchy everything bagel crust.
I’ve been making strata-style breakfast casseroles for years (check out my overnight waffle casserole and savory bread pudding) and this one earns its place in the rotation because it’s truly make-ahead-friendly.
You can assemble it tonight and bake it in the morning, or throw it together and pop it in the oven in 20 minutes flat. Both paths work. The make-ahead version just tastes a little more restaurant-brunch.
It’s veggie-forward, higher in protein than most breakfast casseroles, and the gruyere-parmesan combo gives it a savory depth you don’t get from plain cheddar. You’ll use it for brunch guests, holiday mornings, Sunday meal prep, and every “I need something the kids will actually eat” moment in between.
Why This Everything Bagel Casserole Works
- Make-ahead or now. Assembled and baked in 20 minutes of active time, or soaked overnight for even more flavor.
- Built for a crowd. 9×13 dish feeds 8 generously — one recipe covers a whole family breakfast with leftovers.
- Veggie-loaded. Spinach, cherry tomatoes, and onion pack in nutrition without making this feel like diet food.
- High protein. 8 eggs + chicken sausage + cheese gets you roughly 25g protein per serving.
Bake Now Or Soak Overnight?
The single most-asked question on a breakfast casserole is: bake right away, or let it soak overnight? Here’s the straight answer:
Bake right away: Faster, still delicious, the bagels hold a little more chew. Use this path when you forgot to prep last night.
Soak overnight: Cover tightly and refrigerate 4–24 hours. The bagels absorb the custard more fully, the top crisps more evenly, and the whole casserole bakes up more uniformly fluffy. Best for brunch guests or holiday mornings.
Pro tip: If you’re going the overnight route, cube the bagels the night before you assemble so they stale out a little on the counter. Day-old bagels hold their shape better and won’t turn to mush.
Expert Tips for the Best Texture
- Use plain bagels. Everything bagels make the seasoning flavor too aggressive. Save the everything bagel seasoning for the top.
- Let the bagels dry out. Fresh bagels can go soggy, but day-old or lightly toasted bagels hold their texture.
- Don’t skip the cream cheese chunks. Full-fat brick cream cheese, not whipped, creates those molten pockets people go wild for.
- Check for a clean jiggle. The casserole is done when the center jiggles slightly but doesn’t slosh. Edges should be deeply golden.
- Let it rest 10 minutes before cutting because it continues to set as it cools.
Freezing, Storing, and Reheating
Refrigerate: Store leftovers in an airtight container for up to 4 days.
Freeze baked leftovers: Slice, wrap individual portions in parchment, and freeze in a zip-top bag for up to 2 months. Thaw overnight in the fridge, then reheat in a 350°F oven for 15 minutes or microwave for 90 seconds.
Freeze unbaked: Assemble in a freezer-safe 9×13, wrap tightly in plastic + foil, and freeze up to 3 months. Thaw overnight in the fridge before baking as directed (add 10 minutes to the bake time).
Reheat without drying out: Sprinkle a teaspoon of water over the slice before microwaving, or cover with foil in the oven to trap steam.
What to Serve with Everything Bagel Casserole
Round out brunch with one of these WMM pairings: fresh fruit salsa, healthy banana muffins, berry protein smoothie, or a simple arugula salad with lemon vinaigrette. For holiday mornings, add breakfast sausage or a big batch of crispy bacon.
FAQs
Yes, that’s the recommended method. Assemble everything in the baking dish, cover tightly with plastic wrap or foil, and refrigerate 4–24 hours. In the morning, pull it out 20 minutes before baking to take the chill off, then bake at 375°F for 45–50 minutes until set.
Two common culprits: bagels were too fresh (they collapse under the custard) or the dish wasn’t given enough bake time. Cube bagels the night before to let them stale out, and bake until the center jiggles only slightly and the top is deeply golden.
Absolutely. Swap in 8 ounces of cooked, crumbled bacon or 8 ounces of diced ham. Both work beautifully without changing the bake time.
Yes, both baked and unbaked. Freeze baked slices wrapped in parchment for up to 2 months, or freeze the assembled (unbaked) casserole for up to 3 months. Thaw overnight in the fridge before baking or reheating.
Plain bagels are best because they let the everything bagel seasoning on top do the flavor work. Avoid flavored bagels (asiago, cinnamon raisin, etc.) because they’ll clash. 4 medium plain bagels cut into cubes gives you about 4–4.5 cups.
More Make-Ahead Breakfast Recipes
- Baked protein pancake bowls
- Fluffy egg sandwiches
- High-protein breakfast sandwiches
- Cottage cheese egg bites
Everything Bagel Casserole
Save this Recipe!
Ingredients
- 12 oz uncooked breakfast sausage
- 1 Tablespoon butter or olive oil
- 1 small yellow onion thinly sliced
- 5 oz baby spinach roughly chopped
- 1 cup cherry tomatoes halved
- 2 green onions thinly sliced
- 4 plain bagels 2-3 days old, cut into chunks (around 4-5 cups), I use Dave's Killer Bread
- 10 large eggs
- 2 cups whole milk
- 1/2 cup grated parmesan cheese
- 1/2 cup gruyere cheese shredded, plus more for topping
- Kosher salt and black pepper to taste
- 4 oz full-fat brick cream cheese cut into small cubes
- 2 Tablespoons everything bagel seasoning
Instructions
- Grease a 9×13-inch casserole dish with nonstick spray or olive oil.
- Heat a little olive oil in a large skillet over medium-high heat. Add the sausage and cook until golden brown, making sure it’s cooked through, around 8-10 minutes. Transfer to a paper towel lined plate.12 oz uncooked breakfast sausage
- Add the butter to the same skillet and melt over medium heat. Cook the onion until soft and translucent, around 2-3 minutes. Then add the spinach and cook to wilt, around- 2-3 minutes. Transfer the onion and spinach mixture to the prepared baking dish. Cut the sausage into pieces and add it in with the tomatoes, scallions, and bagels. Toss gently to mix it all if needed, leaving some of the tomatoes on the top.1 Tablespoon butter, 1 small yellow onion, 5 oz baby spinach, 1 cup cherry tomatoes, 2 green onions, 4 plain bagels
- In a separate large bowl, whisk together the eggs, milk, parmesan cheese, gruyere cheese, salt, and pepper. Pour the egg mixture over the bagel and vegetable mixture, pressing it down so the bagels soak up the liquid. Then nestle the cream cheese chunks around the baking dish. Sprinkle on the everything bagel seasoning.10 large eggs, 2 cups whole milk, 1/2 cup grated parmesan cheese, 1/2 cup gruyere cheese, Kosher salt and black pepper, 4 oz full-fat brick cream cheese, 2 Tablespoons everything bagel seasoning
- Cover and refrigerate for at least 2 hours, or overnight, to allow the bagels to absorb the egg mixture.
- When you're ready to bake, preheat the oven to 375°F. Remove the breakfast casserole from the fridge and bake for 50-55 minutes, or until the center is set and the edges are golden brown. Tent with aluminum foil if the top becomes too brown before the center is cooked.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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