Overnight Breakfast Casserole With Sausage & Cheese — Ready

Assemble tonight, bake tomorrow for a hot, crowd-pleasing brunch with melty cheddar and savory sausage—no morning stress, big flavor.

You know that dream where you wake up, wander into the kitchen, and breakfast is already handled? This is that, except real. You spend 20 minutes tonight, and your future self cashes in with a bubbling, golden, cheesy casserole that feeds a crowd. No juggling skillets, no panic pre-coffee, and no last-minute grocery sprints. Just set it, sleep, and claim hero status before noon.

What Makes This Recipe So Good

• Set-and-forget convenience: Build it at night, bake it in the morning. You win back your morning bandwidth.
• Epic flavor payoff: Savory browned sausage, sharp cheddar, and a rich egg custard soak into bread for peak comfort.
• Feeds a crowd without drama: One pan. No flipping, no batches. Brunch for 8–10 is a non-event (in the best way).
• Customizable: Toss in peppers, spinach, or swap cheeses. Make it mild for kids or dial up the heat for spice fans.
• Reliable texture: Custardy center, crisp edges. That perfect contrast so nobody complains the bread is “soggy.” FYI, stale bread is your MVP.
• Budget-friendly: Bread, eggs, sausage, cheese—humble staples that add up to brunch-level wow.

Shopping List – Ingredients

• 1 lb (450 g) breakfast sausage, bulk or casings removed
• 1 tbsp olive oil (only if your sausage is very lean)
• 1 medium yellow onion, diced
• 1 red bell pepper, diced
• 2 garlic cloves, minced
• 8 cups bread cubes (about 12 oz) from sturdy bread like French bread, sourdough, or brioche, preferably day-old
• 2 cups shredded sharp cheddar cheese, divided
• 1/2 cup shredded mozzarella (optional, for extra melt)
• 8 large eggs
• 2 cups milk or half-and-half (half-and-half = richer)
• 1 tsp Dijon mustard
• 1 tsp kosher salt (plus more to taste)
• 1/2 tsp black pepper
• 1/2 tsp smoked paprika
• 1/4 tsp red pepper flakes (optional)
• 2 green onions, thinly sliced
• Cooking spray or butter for the dish
• Fresh parsley, chopped, for garnish
• Optional add-ins: 1 cup sliced mushrooms, 2 cups baby spinach, diced jalapeño, or cooked bacon bits

Step-by-Step Instructions

1. Prep the dish: Grease a 9×13-inch baking dish with cooking spray or butter. This helps the edges crisp and the cleanup stay sane.
2. Cook the sausage: Set a large skillet over medium heat. Add sausage (and olive oil if needed). Break it up and cook until browned and crumbly, about 7–9 minutes. Transfer to a paper towel–lined plate.
3. Soften the veggies: In the same skillet, cook onion and bell pepper with a pinch of salt until tender, 4–5 minutes. Stir in garlic and cook 30 seconds until fragrant. Remove from heat.
4. Cube the bread: Cut bread into 1-inch cubes. If it’s fresh, spread on a sheet pan and toast at 300°F (150°C) for 10–12 minutes to dry it slightly. Drier bread = better custard absorption.
5. Whisk the custard: In a large bowl, whisk eggs, milk (or half-and-half), Dijon, salt, pepper, smoked paprika, and red pepper flakes.
6. Assemble: Add bread cubes to the greased dish. Scatter over the cooked sausage, sautéed veggies, and half the green onions. Sprinkle 1½ cups cheddar (and mozzarella, if using) evenly over the top.
7. Pour and press: Slowly pour the egg mixture all over. Use the back of a spoon to press the bread down so everything gets soaked. Top with the remaining 1/2 cup cheddar.
8. Chill overnight: Cover tightly with foil or wrap and refrigerate 8–24 hours. The soak transforms good into great.
9. Bake: When ready to bake, position a rack in the center and preheat the oven to 350°F (175°C). Bake uncovered for 45–55 minutes, until the top is golden and the center is set. A knife inserted in the center should come out mostly clean, or the internal temp should hit about 160°F (71°C). If the top browns too fast, tent loosely with foil.
10. Rest and serve: Let the casserole rest 10–15 minutes so it slices cleanly. Garnish with remaining green onions and parsley. Serve warm and accept compliments gracefully.

Storage Tips

• Refrigerate: Cool leftovers, then cover and refrigerate for up to 4 days. Reheat slices in a 350°F (175°C) oven for 10–15 minutes or microwave in short bursts.
• Freeze before baking: Assemble, wrap well (plastic + foil), and freeze up to 3 months. Thaw in the fridge 24 hours, then bake as directed, adding 5–10 extra minutes if needed.
• Freeze after baking: Cool completely, wrap tightly, and freeze up to 3 months. Reheat covered at 325°F (165°C) for 30–40 minutes, then uncover for 5 minutes to re-crisp.
• Make-ahead window: Best soaked 8–24 hours. Longer can muddy the texture.

Benefits of This Recipe

• Morning freedom: Your oven does the work while you handle coffee, guests, or that last-minute fruit salad. IMO, that’s priceless.
• Balanced comfort: Protein from eggs and sausage; carbs for staying power; cheese for joy. It’s brunch harmony.
• Scales like a boss: Halve it for a chill weekend, or double it for holidays and potlucks.
• Endless remix potential: Change the cheese, swap the meat, add veg, or lean spicy. You can’t really mess this up if you follow the basics.
• Great leftovers: Meal prep breakfast for days without eating the same boring toast.

Common Mistakes to Avoid

• Using soft, fresh bread: Fresh bread won’t soak evenly and can turn gummy. Dry it out or toast it first.
• Skimping on seasoning: Eggs, bread, and dairy need salt. Taste your sausage; then season the custard accordingly.
• Pouring and running: Don’t skip the overnight rest. The soak is where the magic happens.
• Underbaking the center: If it still jiggles like a water bed, keep baking. Tint the top with foil if browning too fast.
• Skipping the rest after baking: Five to fifteen minutes lets steam settle and slices hold together.
• Overloading wet veggies: Mushrooms and spinach need a quick sauté and drain so they don’t flood the custard.

Different Ways to Make This

• Hash Brown Swap: Replace bread with 24 oz shredded hash browns (thawed and well-dried). Expect a heartier, potato-forward vibe.
• Low-Carb/Keto: Use roasted cauliflower florets and sautéed spinach instead of bread. Reduce milk to 1.5 cups for a firmer set.
• Southwest: Pepper jack + cheddar, a can of mild green chiles, 1 tsp cumin, and a handful of corn. Serve with salsa and avocado.
• Mediterranean: Swap cheddar for feta and mozzarella, add chopped sun-dried tomatoes, baby spinach, and 1 tsp dried oregano.
• All-Bacon or Turkey Sausage: Replace the pork sausage 1:1 with crumbled bacon or turkey sausage.
• Brioche Brunch: Use brioche or croissants for an ultra-rich custard. Fancy without trying too hard.
• Dairy-Free: Use unsweetened almond or oat milk and a good meltable dairy-free cheese, or skip cheese and add extra veggies.
• Gluten-Free: Use your favorite GF loaf—or go the hash brown route.
• Mini Muffin Cups: Grease a muffin tin and bake at 350°F (175°C) for 20–25 minutes for portable portions.

FAQ

Can I assemble it the same morning and still get good results?

Yes, but give it at least 30–60 minutes to soak before baking. The longer overnight rest yields the best texture and flavor, but a shorter soak still works in a pinch.

What’s the best bread to use?

Go for sturdy bread like French bread, sourdough, ciabatta, or brioche. Day-old or lightly toasted bread soaks the custard evenly and avoids sogginess.

Can I use turkey sausage or bacon instead of pork sausage?

Absolutely. Swap 1:1 with turkey sausage, chicken sausage, or crumbled bacon. If your meat is lean, add a splash of oil when browning to prevent dryness.

Why did my casserole turn out soggy?

Likely causes: bread too fresh, too much liquid, or underbaking. Dry the bread first, measure liquids accurately, and bake until the center is set and the top is golden.

How do I know when it’s done?

The center should be just set with minimal jiggle. A knife inserted near the middle should come out mostly clean, or the internal temp should reach about 160°F (71°C).

Can I halve or double the recipe?

Yes. For half, use an 8×8-inch pan and start checking at 30–35 minutes. For double, use two 9×13 pans or a deep roasting pan and extend bake time, checking for doneness.

How can I make it spicier?

Use hot sausage, add diced jalapeños, increase red pepper flakes, and swap in pepper jack cheese. A drizzle of hot sauce at the table never hurts.

Can I make a vegetarian version?

Totally. Skip the sausage and load up with sautéed mushrooms, spinach, and peppers. Add an extra 1/2 teaspoon salt to balance the lost seasoning from the meat.

In Conclusion

This casserole gives you maximum brunch impact with minimum morning effort—exactly how weekends should work. Build it tonight, let the fridge do its thing, and wake up to a golden, savory bake that smells like victory. Guests get fed, you keep your sanity, and your oven gets a well-earned high-five. TBH, this is one of those recipes you’ll memorize and flex on repeat.