Transform stale bagels into a decadent overnight bake. This everything bagel breakfast casserole features a rich cream cheese custard and crispy bacon.
- Stale Bagel Retrogradation: Slightly dried bread structure prevents the custard from turning into a soggy, mushy paste, maintaining a pleasant chew.
- Cream Cheese Pockets: Dropping cold cream cheese blocks on top creates localized pockets of tangy, melted richness that contrast with the savory egg matrix.
- Starch Gelatinization Control: Baking at 375°F ensures the egg proteins coagulate slowly enough to trap moisture without weeping.
My kitchen counter last Sunday was a disaster zone of torn paper bags, half-empty tubs of scallion spread, and three rock-hard everything bagels that had lost their morning luster. My wrist still ached from sawing through their stubborn, leathery crusts with a dull serrated knife, but I refused to let them go to waste. Instead of tossing them, I hacked them into cubes, tossed them with smoky bacon, and drowned them in a rich, mustard-spiked egg bath.
It was hands down a revelation.
Most breakfast bakes turn into a soggy, sad sponge that clings to the roof of your mouth. By utilizing stale bagels, we exploit starch retrogradation—the process where starch molecules recrystallize as bread stales—which keeps the bread structurally sound when drenched in liquid. If you are feeling ambitious and want to bake your own batch first, check out our guide on how to make a Homemade Bagels Recipe from scratch.
If you only have fresh bagels on hand, do not panic. Simply toast the cubes in a warm oven to mimic that dry, moisture-thirsty texture before assembling.
For the salt, I always reach for Diamond Crystal kosher salt — 1 tsp of this light flake equals ½ tsp of standard table salt, which prevents the custard from becoming a salt bomb. I whisked the eggs and whole milk in a heavy glass bowl, watching the yellow yolks break and emulsify into a pale, uniform cream, similar to the custard structure of a classic Quiche Recipe. Dropping cold cubes of brick cream cheese over the top felt a tad clumsy, but those pockets of pure, unadulterated tang are absolutely non-negotiable.
This bake is incredibly forgiving, much like our classic Easy Make-Ahead Breakfast Casserole. It is the ultimate way to feed a crowd without waking up at dawn.
Everything Bagel Breakfast Casserole
Ingredients
- 3 stale everything bagels, cut into 1-inch bite-size cubes (about 6 cups)
- 1 medium bell pepper, finely chopped
- 3/4 cup (113g) cherry tomatoes, quartered
- 6 slices thick-cut bacon, cooked and chopped
- 9 large eggs
- 1 and 1/2 cups (360ml) whole milk
- 1 and 1/2 cups (150g) shredded cheese (such as a mix of mozzarella and smoked gouda)
- 1/2 teaspoon ground mustard
- 1/4 teaspoon Diamond Crystal kosher salt (or 1/8 tsp table salt)
- 1/8 teaspoon freshly ground black pepper
- 6 ounces (170g) full-fat brick cream cheese, cut into small cubes
- Optional garnish: everything bagel seasoning and chopped scallions
Directions
- Preheat your oven to 375°F (191°C). Generously grease a 9×13-inch baking pan or a similar 3-quart casserole dish with butter or nonstick spray.
- Scatter the stale bagel pieces, chopped bell pepper, quartered tomatoes, and chopped bacon evenly across the bottom of the prepared baking dish.
- In a large mixing bowl, vigorously whisk together the eggs, whole milk, shredded cheese, ground mustard, salt, and black pepper until the mixture is completely blended. Pour this liquid custard evenly over the bagel layers, ensuring all the bread pieces get wet.
- Dot the surface of the casserole evenly with the cream cheese cubes, then sprinkle generously with everything bagel seasoning if you are using it.
- Bake for 40 to 50 minutes, or until the center is completely set and no longer jiggles, and the edges are beautifully puffed and golden brown.
- Remove the dish from the oven and let it rest on a wire rack for 10 minutes. Garnish with chopped scallions before slicing and serving warm.
Notes
Keep these essential tips in mind to guarantee a perfect bake every time:
- Brand & Conversion: Use Diamond Crystal kosher salt for seasoning. If you only have standard table salt, cut the measurement in half (use 1/8 teaspoon instead of 1/4 teaspoon) to avoid over-salting the egg custard.
- Science-Backed Rationale: Stale bagels are crucial because their starch molecules have undergone retrogradation, meaning they have crystallized and lost moisture. This allows them to absorb the egg custard without collapsing into a mushy, structureless paste.
- Workflow Warning: Do not let the top cream cheese cubes burn. If you notice the cream cheese or bagel tops browning too quickly around the 30-minute mark, loosely tent the casserole dish with aluminum foil for the remaining bake time.
- Make-Ahead Prep: You can assemble this entire casserole up to 24 hours in advance. Cover it tightly with plastic wrap and store it in the refrigerator; when ready to bake, let it sit on the counter for 20 minutes to shed the chill before placing it in the preheated oven.
- Freezing Instructions: To freeze unbaked, wrap the assembled casserole in plastic wrap and then heavy-duty foil for up to 3 months. Thaw completely in the refrigerator overnight before baking as directed.
- Cream Cheese Hack: Brick cream cheese is typically sold in 8-ounce packages. Rather than saving a tiny 2-ounce scrap, feel free to use the entire 8-ounce block for extra creamy pockets throughout the bake.
Serving Suggestions
To balance the rich, savory profile of this bake, pair it with sides that offer bright acidity or fresh textures:
- Crisp Green Salad: Pair a warm slice with a bright, lemon-dressed arugula salad to cut through the rich, buttery cream cheese pockets.
- Hot Sauce Drizzle: Splash a vinegar-forward hot sauce over the top to provide an acidic contrast to the savory egg custard.
- Smoked Salmon: Serve alongside cold, silky ribbons of smoked salmon to lean into the classic New York deli flavor profile.
- Fresh Fruit Platter: Balance the heavy, salty bacon and bagel cubes with a side of crisp, sweet melon and berries.
- Spicy Condiment: Offer a dollop of chili crisp or jalapeño jelly on the side for a sweet-heat kick that clings to the savory bagel crust.
Storage and Reheating
Once the casserole has cooled completely to room temperature, slice any remaining portions and pack them into airtight containers. In the refrigerator, this savory bake will keep beautifully for up to 5 days, making it an exceptional option for weekday meal prep.
Over time, the bagels will continue to draw moisture from the egg matrix, resulting in a slightly denser texture after 24 hours. However, the flavors actually deepen and meld together, making day-two slices taste even more robust than when freshly baked.
To reheat, avoid the microwave if you want to preserve the crispy edges of the bagel crust. Instead, place individual slices on a parchment-lined baking sheet and warm them in a 350°F (177°C) oven or toaster oven for 8 to 10 minutes until heated through.
If you must use the microwave, heat on medium power in 30-second bursts to prevent the eggs from becoming rubbery and sweating excess moisture onto your plate. For more breakfast prep ideas, check out our Pumpkin Baked Oatmeal which stores and reheats just as beautifully.
Ingredient Substitutes
If you need to swap ingredients based on what is in your pantry, use these direct conversions:
- Stale Everything Bagels: If you don't have everything bagels, use plain stale bagels or a rustic sourdough loaf. Add 1.5 tablespoons of everything bagel seasoning directly to the egg mixture to maintain the signature flavor profile.
- Whole Milk: Swap with unsweetened oat milk or half-and-half at a 1:1 ratio. Avoid skim milk, as the lack of fat will cause the egg custard to break and weep during baking.
- Bacon: Substitute with cooked, crumbled breakfast sausage or vegetarian soy chorizo at a 1:1 ratio. Ensure any meat is fully cooked and drained of excess grease before layering.
- Smoked Gouda & Mozzarella: Use sharp cheddar, pepper jack, or gruyère at a 1:1 ratio. Grate the cheese from a block rather than buying pre-shredded bags, which are coated in starch that prevents smooth melting.
- Ground Mustard: Swap with 1 teaspoon of Dijon mustard whisked directly into the eggs. This maintains the emulsifying properties and sharp acidity needed to balance the rich fats.
There is something incredibly satisfying about turning yesterday's forgotten bagels into a bubbling, golden centerpiece. Pull this out of the oven when the top is puffed and the cream cheese is lightly blistered, and watch your morning crowd gather instantly.
