Overnight Sausage and Caramelized Onion Breakfast Casserole is a great breakfast for the holidays. Full of cubed challah bread, sausage, caramelized onions, and two types of cheese.

Overnight Breakfast Casseroles are perfect for the holidays and I love assembling one on Christmas Eve and popping it in the oven Christmas morning. After 40 minutes in the oven, this casserole gets crispy and golden around the edges. It’s so savory and delicious.
The caramelized onions are what make this an amazingly tasty breakfast casserole. They add a wonderful sweetness and pair perfectly with the sausage.

 
How To Make This Sausage and Caramelized Onion Breakfast Casserole Spicy"
Use “Hot” breakfast sausage and add 1/2 teaspoon of crushed red pepper flakes. Recipe Tips:
Leftovers will keep in an airtight container in the refrigerator for 4 to 5 days. Can be reheated in the microwave, air fryer, or toaster oven.
Not only for the holidays, this casserole works anytime of year.
French or Italian Bread can be used instead of challah bread.
When you take it out of the oven, check to make sure the center is set and not runny. If the top starts to get too browned before it is done, cover it with foil.

I’m a huge fan of breakfast casseroles. They’re so easy for feeding a house full of people.
Try These Other Amazing Breakfast Casseroles:

Sausage and Crescent Roll Casserole
Breakfast Tater Tot Casserole
Sausage and Cheese English Muffin Casserole
Eggs Ben...