Overnight Breakfast Casserole Recipe (Make-Ahead Favorite)

If mornings feel hectic—or you just like sleeping in—a warm, hearty overnight breakfast casserole might just become your favorite thing. It’s the kind of comfort food that’s not only delicious but incredibly practical. Prep it at night, pop it in the oven the next morning, and boom—breakfast is done. Whether it’s for holiday brunch, a weekend family gathering, or a lazy Sunday, this cheesy, eggy, sausage-packed bake is satisfying and surprisingly simple.

Let’s walk through everything step-by-step, with some handy tips along the way.

Ingredients You’ll Need

This casserole uses pantry staples and breakfast favorites. You can always tweak it based on what’s in your fridge.

8 large eggs
2 cups whole milk (or half-and-half for creamier texture)
1 tsp salt
½ tsp black pepper
1 tsp garlic powder
½ tsp onion powder
1½ cups shredded cheddar cheese
1 cup shredded mozzarella
1 lb breakfast sausage, cooked and crumbled
6 cups bread cubes (day-old bread works best—think French, sourdough, or sandwich bread)
Optional: diced bell peppers, green onions, or baby spinach for a veggie boost

How to Make Overnight Breakfast Casserole

The best part? You mix it, chill it, and bake it in the morning. No morning chaos. No mess.

Grease a 9×13” baking dish lightly with butter or spray.
Spread bread cubes evenly in the dish.
Top with cooked sausage, shredded cheese, and any veggies you’re using.
In a large bowl, whisk together eggs, milk, salt, pepper, garlic powder, and onion powder.
Pour the egg mixture slowly over the casserole, making sure to soak all the bread.
Cover tightly with foil or plastic wrap and refrigerate overnight (at least 8 hours).
In the morning, preheat oven to 350°F (175°C). Remove the wrap.
Bake for 45–50 minutes, or until the top is golden and the center is set. If the top browns too fast, tent with foil.

Let it cool for about 5–10 minutes before slicing. You’ll thank yourself later.

Time & Serving

Prep Time: 15 minutes
Chill Time: Overnight (8–12 hours)
Bake Time: 45–50 minutes
Serves: 8–10 people

Kitchen Tools You’ll Need

9×13-inch baking dish
Mixing bowl
Whisk
Measuring cups and spoons
Aluminum foil or plastic wrap
Skillet (for sausage)
Spatula for serving

Extra Tips to Make It Perfect

Use day-old bread: Fresh bread can get soggy. Day-old holds up better after soaking overnight.
Sausage swap? Turkey sausage or even diced ham work great. Vegetarian? Use mushrooms and extra cheese.
Want a crispy top? Sprinkle a little extra shredded cheese on top before baking.
Cheese combos: Don’t stop at cheddar. Pepper jack, gruyère, or Colby jack melt beautifully.

How to Serve It

This casserole is a meal on its own, but here are a few pairing ideas:

A side of fresh fruit or berries
A scoop of cinnamon sugar baked donuts (yes, dessert-for-breakfast is a vibe)
Hot coffee or orange juice
Maybe a drizzle of hot sauce or ketchup for those who like a little kick

Storage Tips

Leftovers? You’re in luck—this reheats beautifully.

Refrigerate: Store in an airtight container for up to 4 days.
Reheat: Microwave individual slices for 1–2 minutes or bake in a 300°F oven until warm.
Freeze: Slice into portions, wrap well, and freeze up to 2 months. Thaw in the fridge overnight before reheating.

Nutrition (Per Serving – Approx.)

Calories: 310
Protein: 18g
Carbs: 17g
Fat: 20g
Fiber: 1g
Sugars: 2g
Sodium: 580mg

Nutritional info may vary slightly based on ingredients used.

Recipe Notes

You can prep this up to 24 hours in advance.
Want it extra rich? Swap some of the milk for cream.
If using pre-cooked sausage, save time by skipping the skillet step.
For added flavor, try adding a pinch of paprika or dried herbs to the egg mix.

FAQs: Related to Cinnamon Sugar Baked Donuts

Since folks who love breakfast casseroles often love baked donuts too, here are some quick answers that might help:

Yes, you can! The shape won’t be the same, but the flavor holds up. Just adjust baking time slightly.

A quick dip in melted butter, then toss in a mix of granulated sugar and cinnamon. Let them sit for a bit—it sticks better.

Absolutely. Let them cool completely, then freeze in a sealed container for up to 2 months. Reheat in the oven.

Yes—substitute with applesauce or yogurt. The texture may be a bit different, but still tasty.

They’re best fresh, but you can store them in an airtight container at room temperature for up to 3 days.

Conclusion:

There’s something comforting about waking up to a warm, ready-to-bake breakfast—especially one that doesn’t require you to juggle a dozen things before coffee. This overnight breakfast casserole checks all the boxes: it’s filling, flexible, and practically made for sharing.

Whether it’s a special morning or just another busy weekday, having a no-stress breakfast like this one tucked in the fridge makes life a little easier—and tastier. Give it a try this weekend, or prep it tonight for tomorrow’s breakfast. Either way, you’ll be glad you did. If you try this recipe, I’d love to hear how it went—or what little twists you added to make it your own.

Happy baking. 🍳