Overnight Bisquick Breakfast Casserole

Looking for a hearty, make-ahead breakfast that brings the whole family to the table? My Overnight Bisquick Breakfast Casserole is the answer.

Packed with savory sausage, crispy bacon, sharp cheddar cheese, and the perfect blend of eggs and Bisquick, this dish is a comforting classic.

Whether you’re prepping for a holiday morning, weekend brunch, or a busy weekday, this casserole bakes up warm and satisfying—straight from your fridge to the oven.

Let’s dive into everything you need to make this easy breakfast casserole that’s sure to become a family favorite.

Ingredients List

This recipe brings together a handful of simple, flavorful ingredients. Here’s what you’ll need:

Main Ingredients

• 1 lb. ground pork sausage (I like using Country Mild, but feel free to spice it up with hot sausage)
• ½ lb. bacon
• ½ cup finely-diced green bell pepper
• ½ cup finely-diced onion
• 2 cups grated sharp cheddar cheese
• 6 large eggs
• 3 cups whole milk (you can also use heavy cream for a richer texture)
• 1 cup Bisquick (or any all-purpose baking mix)
• ½ cup salted butter, melted

Optional Garnish

• Sliced green onions
• Fresh herbs like chopped parsley or chives

These ingredients combine into a rich, creamy casserole that’s full of texture, flavor, and comfort. Now let’s talk about the tools that’ll make your prep easier.

Required Kitchen Tools

To make this casserole a breeze from start to finish, here are the tools I recommend having ready:

1. Large Skillet: You’ll use this to brown the sausage and fry the bacon.
2. Mixing Bowls: A couple of medium to large bowls will help you whisk and combine the wet ingredients smoothly.
3. Whisk: Essential for combining eggs, milk, and Bisquick evenly.
4. 9×13-inch Baking Dish: This is the perfect size for this casserole and ensures even baking.
5. Nonstick Cooking Spray: Helps prevent sticking and makes cleanup easier.
6. Sharp Knife and Cutting Board: For dicing onions, peppers, and herbs.
7. Paper Towels: Handy for draining the bacon after frying.

Having these tools nearby will make your cooking process efficient and enjoyable.

Preparation and Assembly

Making this breakfast casserole is a simple, no-stress process that lets you prep the night before and enjoy your morning. Follow these step-by-step instructions for foolproof results:

Step 1: Prepare Your Baking Dish

Start by spraying a 9 x 13-inch baking dish with nonstick cooking spray. This ensures an easy release and makes cleanup a breeze.

Step 2: Cook the Sausage

In a large skillet over medium-high heat, brown the ground pork sausage until it’s fully cooked and no longer pink. Use a spatula to break it up as it cooks so you get bite-sized crumbles throughout the casserole. Once it’s done, drain the excess grease and transfer the sausage into your prepared baking dish.

Step 3: Fry the Bacon

Using the same skillet (no need to wash it—hello flavor!), fry the bacon until crispy. Transfer the cooked bacon to a paper towel-lined plate to absorb extra grease. Once cool, chop or crumble the bacon and add it to the baking dish with the sausage.

Step 4: Add the Veggies and Cheese

Now for that extra burst of color and crunch: add your finely diced green bell pepper and onion right into the baking dish. Top it all with the grated sharp cheddar cheese—this is where the creamy, cheesy magic starts.

Step 5: Mix the Egg Mixture

In a large mixing bowl, whisk together the eggs, whole milk (or cream), Bisquick mix, and melted butter until smooth and fully combined. This mixture will bake up into a fluffy, golden base for your casserole.

Step 6: Combine and Chill

Pour the egg mixture over the sausage, bacon, veggies, and cheese in the baking dish. Use a spatula or spoon to gently stir and ensure everything is evenly distributed. Then, cover the dish with plastic wrap or foil and refrigerate overnight. This resting time lets the flavors meld and ensures a perfect bake in the morning.

Baking and Serving Instructions

You’ve done the prep, and now it’s time to bring this breakfast casserole to life. Here’s exactly how to bake it for the best texture, flavor, and golden-brown finish.

Step 1: Let It Come to Room Temperature

When you’re ready to bake, take the casserole out of the fridge and let it sit at room temperature for 30 to 60 minutes. This step helps it cook evenly and prevents a cold center.

Step 2: Preheat and Bake

Preheat your oven to 350°F (175°C). Once the casserole has warmed up a bit, remove the cover and bake it uncovered for 50–60 minutes.

You’ll know it’s done when:

• The top is lightly browned
• The center is set and no longer jiggly
• A knife inserted in the middle comes out clean

Step 3: Let It Rest

Once baked, let the casserole rest for at least 10 minutes before slicing. This allows the structure to firm up, making each piece easier to serve without falling apart.

Step 4: Garnish and Serve

Just before serving, sprinkle sliced green onions or fresh chopped herbs over the top for a burst of color and freshness. Parsley, chives, or even a little thyme work beautifully.

Storage Instructions

Whether you’re feeding a crowd or meal-prepping for the week, this casserole keeps well and reheats beautifully. Here’s how to store it properly so you can enjoy every last bite.

Refrigerating Leftovers

If you have leftovers, allow the casserole to cool completely. Then:

• Cover the dish tightly with foil or transfer slices to an airtight container.
• Store in the refrigerator for up to 4 days.
• To reheat, microwave individual slices for 1–2 minutes or warm in a 300°F oven until heated through.

Freezing for Later

Want to make this ahead for even longer storage? This recipe is freezer-friendly!

• After baking and cooling, cut the casserole into serving-size portions.
• Wrap each piece in plastic wrap, then place in a freezer-safe container or zip-top bag.
• Freeze for up to 2 months.
• Thaw overnight in the fridge and reheat in the oven or microwave when ready to eat.

Conclusion

This Overnight Bisquick Breakfast Casserole is one of my favorite go-to recipes when I want something easy, comforting, and crowd-pleasing. It checks all the boxes: rich, cheesy, savory, and customizable. The best part? It saves you time in the morning while still delivering homemade warmth and flavor.

You can even make it your own by swapping in different meats (ham, turkey sausage), veggies (spinach, mushrooms), or cheeses (pepper jack, mozzarella). Whether you’re prepping for a holiday breakfast, Sunday brunch, or just need a solid weekday meal—this casserole will never let you down.