This Everything Bagel Breakfast Casserole is the Perfect Make-Ahead Brunch
If you’ve ever stared at a few day-old bagels and wondered what to do with them—this casserole is your answer. It’s cozy, savory, packed with veggies and protein, and comes together with minimal prep. Whether you’re hosting brunch, planning a holiday breakfast, or just trying to meal prep for a busy week, this casserole checks all the boxes.
Think: soft bagels soaked in cheesy eggs, bites of juicy sausage, fiber-rich spinach, sweet cherry tomatoes, and golden edges sprinkled with everything bagel seasoning. Oh—and cream cheese baked right in.
It’s everything you love about a bagel sandwich, baked into one pan.
Make It Ahead or Bake It Fresh
This recipe is super flexible. My favorite way is to assemble everything the night before and bake it fresh in the morning, which makes it ideal for entertaining or easing into a slow Sunday. But if you’re short on time, use fresh bagels and bake it right away. Use what you have in the time you have!
Variations + Swaps
- Cheese: Don’t have gruyere? Shredded cheddar or mozzarella works great.
- Sausage: Swap for bacon, ham, or even go meatless—just add more veggies or plant-based sausage.
Love breakfast casseroles? Try overnight waffle casserole or savory bread pudding next!
More Make-Ahead Breakfast Recipes
- Baked protein pancake bowls
- Fluffy egg sandwiches
- High-protein breakfast sandwiches
- Cottage cheese egg bites
Everything Bagel Casserole
This Everything Bagel Breakfast Casserole is a high-protein, veggie-packed dish made with bagels, sausage, spinach, tomatoes, and a cheesy egg mixture. It's perfect for meal prep or weekend brunch and can be baked right away or prepped the night before for an easy, flavorful morning.
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Servings: 8 servings
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 Plain Awesome Bagels
- 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.
Last step! If you make this, please leave a review letting us know how it was!
Notes
Protein Options. You can swap the breakfast sausage for crispy bacon or ham. Leave it out for a vegetarian option.
Cheese. I tested this with gruyere and a gruyere and white cheddar cheese mixture. You could use all white cheddar cheese or another white cheese like muenster cheese or mozzarella.
Homemade Everything Bagel Seasoning. Combine 1 tablespoon each of white sesame seeds, black sesame seeds, dried minced garlic, dried minced onion, and poppy seeds with 1 teaspoon of flaky sea salt or kosher salt. Mix everything together in a small bowl or jar,
Quicker Option (No Refrigerating). I also tested this without refrigerating the casserole to save time. It had slightly less of a custard texture and more of an egg bake texture because the bagels don’t have as much time to absorb the liquid. I prefer the custard texture (similar to a french toast casserole), but this way it still delicious, so you can do it this way if you’re short on time!
Storage and Reheating. Leftovers keep well in the fridge for up to 4 days. Just pop individual slices in the microwave for about 30–60 seconds or reheat in a 300°F oven until warmed through. It’s a great one to prep for weekday breakfasts, too.
Nutrition
Serving: 8servings | Calories: 410kcal | Carbohydrates: 29g | Protein: 26g | Fat: 21g | Saturated Fat: 10g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 6g | Trans Fat: 0.2g | Cholesterol: 235mg | Sodium: 986mg | Fiber: 2g | Sugar: 5g | Vitamin A: 2517IU | Vitamin C: 12mg | Calcium: 292mg | Iron: 3mg
Nutrition information is automatically calculated, so should only be used as an approximation.
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