Ultimate Cheesy, Make-Ahead Egg Bake Casserole
A custardy, protein-packed casserole that's perfect for make-ahead breakfasts, feeding a crowd, and can be customized with various mix-ins.
Ingredients
Custard Base
- 12 large large eggs
- 1 cup milk or half-and-half Half-and-half yields a richer custard.
- 1 cup cottage cheese Optional for extra protein and fluffier texture.
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1/2 teaspoon garlic powder
- 1/4 teaspoon onion powder
Cheeses
- 1 cup shredded cheddar cheese Divided: ¾ cup mixed into the custard; ¼ cup for the top.
- 1 cup shredded Monterey Jack cheese
Mix-ins
- 1 cup cooked, crumbled breakfast sausage or diced ham Swap for bacon if preferred.
- 1 cup fresh spinach, chopped Baby spinach works great.
- 1 cup sliced mushrooms Sauté first if you don’t want extra moisture.
Instructions
Preparation
- Preheat the oven to 375°F. Lightly grease a 9x13-inch baking dish.
- In a large bowl, whisk the eggs with the milk or half-and-half, cottage cheese (if using), salt, black pepper, garlic powder, and onion powder until well combined and slightly frothy.
- Stir 3/4 cup of the shredded cheddar and all of the Monterey Jack into the egg mixture. Add the cooked sausage or diced ham, chopped spinach, and sliced mushrooms. Mix gently so the fillings are evenly distributed.
- Pour the entire mixture into the prepared baking dish and smooth the top.
- Sprinkle the remaining 1/4 cup of cheddar evenly across the surface.
Baking
- Bake for 35 to 45 minutes, or until the center is set and a knife inserted near the middle comes out clean. If baking from cold, add 10–15 minutes to the bake time.
- Let the egg bake rest for 5 minutes before slicing and serving.
Notes
This casserole is great reheated and can be customizable per dietary needs. Cool the casserole and refrigerate for up to 4 days or freeze individual slices for up to 3 months.