Easy and delicious, breakfast casserole with sausage and spinach can be made the night before. Enjoy it for breakfast, lunch, or dinner!
Why you’ll love it: You can prep this casserole up to a day ahead and bake it when you need it. It’s really good leftover, too!
How long it takes: about 15 minutes to prep and 50 minutes to bake
Equipment you’ll need: 9 x 13 inch baking dish, mixing bowl, skillet
I love to cook with my mom. Whenever we spend time together, half of it is spent in the kitchen. We were cooking together this past weekend and she said, “Isn’t it fun to cook with other people?”
I said yes almost without thinking, but then after taking a moment to think about it, I realized that my mom is one of the only people who I truly enjoy cooking with.
I can be a bit of a control freak but with my mom that is never an issue. We have similar styles, we communicate well, and we can easily divide tasks without a discussion.
Awhile back, we were baking for a birthday party, making pretty in pink cupcakes. We started the day off with this hearty breakfast casserole with sausage and spinach (and plenty of coffee) so we had plenty of energy to accomplish what we needed to get done.
This overnight casserole recipe with bread is one that my mom always made on Christmas morning for brunch. While a breakfast casserole is perfect for special occasions, we also enjoy it year round. It’s a great-tasting savory breakfast but hearty enough for dinner, too.
About This Recipe
- This breakfast casserole has simple ingredients and it’s easy to make. There’s nothing fancy about this recipe and that’s why so many people love it. It’s just plain good eating. It’s an easy make-ahead recipe which makes it a good choice for busy holidays or when you have overnight guests.
- A breakfast casserole is a healthy choice. A serving of this casserole packs in 18 grams of protein, with sausage, eggs, milk, and cheese. You’ll get a good serving of greens as well.
- It’s a great way to use day-old bread. I consider stale bread a treasure. I use it to make this breakfast casserole, homemade croutons, which are tons better than packaged croutons, or my own bread crumbs. Use stale bread to make an amazing panzanella salad or an asparagus panzanella salad in the spring.
Ingredients You’ll Need
- Breakfast Sausage (pork or turkey): Look for bulk sausage, not links. It is often sold in a tube (chub). Choose whatever brand or variety you like best.
- Baby Spinach: The small tender leaves of baby spinach cook very quickly. Look for a 5 oz. container (about 4 cups loosely packed). I’ve used frozen spinach, too, but fresh spinach has much better flavor. Any tender green will work.
- Eggs: This casserole is made with 8 eggs. Eggs are nutritious and inexpensive.
- Milk: For the creamiest casserole, use whole milk. I’ve often made it with 2% and it’s fine but I would avoid nonfat or skim milk because it tends to get watery.
- Bread: Plain white bread works best. I like to use bakery bread because it’s a little more porous and absorbs the egg mixture better. Day old bread is perfect; it’s best when it’s a little dry. To be honest, I’ve used just about any bread for this casserole, even leftover dinner rolls.
- Cheese: Cheddar cheese goes well with the sausage and spinach but feel free to sub in a different kind of cheese. Shred your own cheese for the best texture but pre-shredded cheese is fine, too.
- Seasoning: The sausage provides most of the seasoning but a bit of salt, pepper, and mustard powder add just the right flavor.
How To Make This Breakfast Casserole
Begin by browning the sausage. Put the sausage into a large skillet, breaking up the large chunks as it browns. It takes about 5 minutes. If the sausage seems greasy, drain off the excess fat. Arrange the sausage in an even layer in the bottom of a greased 9 x 13 inch glass baking dish.
Wilt the spinach. Put the spinach into the same skillet, cover, and cook it until it’s wilted, giving it a stir now and then. It will look like a lot of spinach at first but it really cooks down in just a few minutes. Arrange the cooked spinach on top of the sausage.
Add a layer of cheese. Sprinkle 1 cup of the cheese over the spinach.
Cube the bread and add it to the baking dish. The bread should be cut or torn into cubes or small chunks. Arrange it in an even layer on top of the cheese.
Whisk the eggs, milk, and seasonings.
Once they are well blended, pour the egg mixture over the contents of the baking dish. The bread should be soaked with the mixture; lightly push down any bread that is protruding above the eggs. Sprinkle on the remaining cheese.
Refrigerate or bake. At this point, the casserole can be covered and refrigerated for up to 24 hours. When you’re ready to bake it, remove the casserole from the fridge and uncover it. Preheat the oven and bake the casserole until it’s set in the middle. Let it cool for 5 minutes or so before cutting and serving.
I definitely recommend refrigerating breakfast casseroles, unbaked or baked, because they contains dairy products, eggs, and meat. Leaving casseroles at room temperature invites the growth of bacteria and you may get a food-borne illness. Promptly refrigerate leftovers. If the casserole has been at room temperature for more than 2 hours, it should probably be discarded.
A quiche is a pie with a pastry-type crust and an egg filling. Try one of these recipes: Bacon Cheddar Quiche with Sweet Potato Crust, Turkey Sausage and Asparagus Quiche, and Spinach Quiche with Cornmeal Crust.
A breakfast casserole doesn’t have a crust. It’s usually made with bread soaked in an egg mixture. Try my Overnight French Toast Casserole or Crescent Roll Breakfast Casserole.
What Goes Well With Breakfast Casserole?
- Fruit! Juicy sweet fresh fruit complements egg casseroles. Try a citrus salad or fruit kabobs with cream cheese fruit dip. Fresh green salads like a classic arugula salad with lemon basil vinaigrette go well, too.
- Vegetables: I love to serve roasted vegetables with breakfast casseroles. Crispy roasted potatoes or oven roasted sweet potatoes go well. Try roasted carrots or roasted radishes.
- Bread: Muffins and breads go well with egg casseroles. My whole wheat banana bread is always a hit. Serve it with vanilla bean whipped cream cheese. You can’t go wrong with blueberry cream cheese muffins or pumpkin streusel bread.
- Drinks: Looking for a brunch cocktail? Try hibiscus mimosas or white wine spritzers.
Ways To Change It Up
- Substitute your favorite veggies for the spinach. Try red or green bell peppers, onions, mushrooms, or broccoli.
- Use a different kind of cheese. Try feta or Swiss. Substitute ham for the sausage, or use turkey sausage.
- Make it vegetarian. Substitute mushrooms or another vegetable for the sausage, or simply omit it.
- Looking for something a little out of the ordinary? Try a ham, spinach, and cheese egg boat or sheet pan breakfast tostadas. Lately we’ve been loving sheet pan eggs. They are so easy to prepare and are ready to eat in about 15 minutes.
Make Ahead Ideas
One of the things I really love about this casserole is that you can prepare it hours ahead, even the night before, and bake it when you’re ready.
I like to make a big 9 x 13 pan for dinner, and then we eat it for breakfast during the week. It’s just as good reheated and you can’t beat a yummy hot casserole that can be warmed up in the microwave in a snap.
Storage & Reheating Tips
- Refrigerate: Unbaked casserole can be refrigerated for up to 24 hours. Baked casserole will keep in the refrigerator for up to 3 days.
- Reheat: Microwave individual portions of baked casserole briefly until warmed through. It heats up pretty quickly.
- 1 pkg. (16 oz.) ground breakfast sausage (pork or turkey)
- 4 cups fresh baby spinach, loosely packed (5 oz. container)
- 8 large eggs
- 2 ½ cups milk (see note)
- 1 ½ teaspoons dry mustard powder
- ¼ teaspoon kosher salt
- ¼ teaspoon coarse ground black pepper
- 8 slices white bread (14 oz.), cut into cubes (see note)
- 2 cups shredded cheddar cheese, divided (8 oz. pkg.)
- Preheat oven to 350°F. Lightly spray a 9 x 13 inch glass baking dish with cooking spray.
- Brown sausage in a large frying pan over medium heat, breaking up clumps as it browns. Transfer cooked sausage to a paper-towel lined plate to drain fat. Spread sausage on the bottom of the baking dish.
- Wilt spinach in the same pan over medium heat, covered, tossing occasionally, for a couple of minutes. Arrange spinach over the sausage layer. Sprinkle on 1 cup of cheese. Add the bread cubes in an even layer.
- In a large bowl, whisk together eggs, milk, salt, pepper and dry mustard powder. Pour egg mixture evenly over bread. Press bread down a little, if needed, so that all of it is soaked with the egg mixture. Sprinkle remaining 1 cup cheese over the top. At this point the egg casserole can be be covered and refrigerated for up to 24 hours (see note).
- Bake for 45 to 50 minutes or until set. To check for doneness, insert a table knife in the center of the casserole. It should come out clean. Remove from oven and let stand for at least five minutes before serving.
- Whole milk makes the creamiest casserole but either 2% or low fat milk work fine, too.
- Day old dry bread is best. Use white or whole wheat bread. I like to use a combination of white and wheat bread.
- Nutrition information is calculated using pork sausage, 2% milk, and white bread.
- Make ahead: Prepare breakfast casserole, as directed, but don’t bake. Cover tightly, and refrigerate several hours or overnight. Remove casserole from refrigerator while oven preheats so it warms up slightly. Increase baking time, if necessary.
- You can substitute pretty much anything for the vegetables and meat. Try one of these combinations: Sausage and Mushroom, Ham and Broccoli, or Spinach, Red Peppers & Feta.
- Substitute your favorite cheese for the cheddar.
- Vegetarian: Omit the sausage, and increase the veggies.
This website provides approximate nutrition information for convenience and as a courtesy only. Nutrition data is gathered primarily from the USDA Food Composition Database, whenever available, or otherwise other online calculators.