A great make-ahead breakfast casserole is the perfect back-pocket recipe for when you’re hosting overnight guests. Do all the work the night before, then pop it in the oven the next morning for a decadent and special occasion-worthy meal. Your guests will love that you went the extra mile to make them feel special, and no one has to know how easy it was to prepare!
I like to think of this recipe as a “choose your own adventure” breakfast casserole. Keep in mind a few key ratios, but substitute ingredients based on what you have or what you’re craving.
Key Ingredients in This Breakfast Casserole
- Crusty bread: Day-old bread also works great here, as it will absorb the eggs and milk in the casserole. This becomes the first layer of the casserole in the baking dish.
- Protein and veggies: Here I sautéed some green onion with bulk breakfast sausage, but you can also use this as an opportunity to repurpose leftover ingredients. Cubed leftover ham is a great choice, as are broccoli florets and sliced mushrooms for a vegetarian option.
- Shredded cheese: Cheddar is always a solid choice, but I think melty and delicious fontina is also a great option. If you want a spicy kick, try pepper jack cheese.
- Eggs and milk: For 8 ounces of bread, you will need 6 large eggs and 1 cup of milk to hold everything together.
- Herbs and seasoning: I love smoked paprika, so that’s what I added here. But feel free to get creative and use your favorite herbs or seasoning to make the casserole your own.
Why Is My Breakfast Casserole Runny?
The key to a breakfast casserole that is moist and delicious but not runny is to make sure you have the proper ratio of bread, eggs, and milk. If there is too much liquid for the bread to absorb, the result could be a runny casserole. This is why I like a firmer bread like a crusty French bread or a baguette rather than something softer, like challah. I have found the ratio of about 8 ounces of cubed bread, 6 eggs, and 1 cup of milk works well for breakfast casseroles.
Breakfast Casserole
Serves 6
8 ounces crusty French bread or baguette
4 teaspoons olive oil, divided
2 medium scallions
4 ounces cheddar cheese
8 ounces uncooked breakfast sausage
6 large eggs
1 cup whole milk or 2% milk
1 teaspoon smoked paprika, plus more for sprinkling
1/2 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
1. Drizzle a 2-quart baking dish, such as an 8-inch square, with 2 teaspoons of the olive oil. Cut 8 ounces crusty French bread or baguette into 1-inch cubes. Place in the baking dish and arrange into an even layer.
2. Thinly slice 2 medium scallions, keeping the dark green parts separate from the white and light green parts. Grate 4 ounces sharp cheddar cheese on the large holes of a box grater (about 1 cup). Remove 8 ounces uncooked breakfast sausage from the casings if needed.
3. Heat the remaining 2 teaspoons of olive oil in a large skillet over medium-high heat until shimmering. Add the sausage and white and light green scallion parts. Cook, breaking up the sausage into bite-sized pieces with a wooden spoon, until the sausage is browned and cooked through, about 5 minutes. Transfer the sausage mixture evenly over the bread. Sprinkle with the cheese.
4. Place 6 large eggs, 1 cup whole milk or 2% milk, 1 teaspoon smoked paprika, 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper in a large bowl and whisk until combined. Pour evenly over the bread mixture. Press down on the bread so it soaks up the liquid. Cover and refrigerate for at least 8 or up to 24 hours. (Alternatively, the casserole can be baked right away: Let it sit at room temperature while the oven heats so the bread has time to absorb the custard.)
5. Arrange a rack in the middle of the oven and heat the oven to 350 F. If the casserole has been refrigerated, let it sit at room temperature while the oven is heating.
6. Uncover and bake until lightly browned on top and a tester inserted into the center comes out clean, 30 to 50 minutes. Let cool for 5 minutes before serving. Sprinkle with more paprika and garnish with the reserved dark green scallion parts.
Recipe notes: Leftovers can be refrigerated in an airtight container for up to four days. The casserole can also be cut into portions, tightly wrapped, and frozen for up to three months.
