Easy Breakfast Casserole Recipe From Scratch

Breakfast casserole is one of those recipes I keep on repeat. It feeds a crowd with almost no hands-on time, and it reheats better than most hot breakfasts. This version uses turkey sausage, frozen diced potatoes, bell pepper, eggs, and sharp cheddar for a layered bake that holds together on a plate.

Why This Breakfast Casserole Works

Frozen diced potatoes skip all the peeling and chopping. They absorb the egg mixture overnight and hold their shape after baking. The result is a sturdy base with crisp edges.

Turkey sausage adds savory depth without the grease pools that pork sausage leaves behind. It browns fast and crumbles evenly through every slice.

Sharp cheddar melts into a golden top layer with slight pull. A full two cups keeps the flavor strong from the first bite to the last corner piece.

Ingredients

• 1 pound turkey breakfast sausage
• 1 tablespoon olive oil
• 1 medium yellow onion, diced
• 1 medium red bell pepper, diced
• 4 cups frozen diced hash brown potatoes
• 8 large eggs
• 1 cup whole milk
• 1/2 cup sour cream
• 2 cups shredded sharp cheddar cheese
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1/2 teaspoon garlic powder
• 1/4 teaspoon smoked paprika

What You Need for Breakfast Casserole

Turkey breakfast sausage — pre-seasoned rolls work best. Pork sausage is fine if you prefer it. Brown and drain the fat before adding to the casserole.

Frozen diced hash brown potatoes — these save 20 minutes of peeling and dicing. Use them straight from the freezer. Shredded hash browns work but make a softer texture.

Sour cream — this is the secret to a creamy egg base that does not dry out in the oven. Greek yogurt substitutes at a 1:1 ratio.

Sharp cheddar cheese — buy a block and shred it yourself. Pre-shredded bags contain anti-caking starch that blocks smooth melting.

Red bell pepper — adds crunch and a mild sweetness. Green pepper works for a sharper flavor.

Smoked paprika — a small amount rounds out the sausage flavor. Regular paprika is a fine swap.

How to Make Breakfast Casserole

1. Preheat the oven to 350 degrees F (175 degrees C). Grease a 9×13 inch baking dish.
2. Heat olive oil in a large skillet over medium-high heat. Add turkey sausage and cook for 6 minutes, breaking it into crumbles, until browned.
3. Add diced onion and bell pepper to the skillet. Cook for 3 minutes until softened.
4. Spread frozen hash brown potatoes in an even layer across the bottom of the baking dish.
5. Scatter the sausage and vegetable mixture over the potatoes.
6. Whisk eggs, milk, sour cream, salt, pepper, garlic powder, and smoked paprika in a large bowl until smooth.
7. Pour the egg mixture evenly over the casserole layers.
8. Top with shredded sharp cheddar cheese in an even layer.
9. Bake uncovered at 350 degrees F for 45 minutes until the center is set and the cheese is golden and bubbling.
10. Let the casserole rest for 10 minutes before slicing into 8 pieces.

Breakfast Casserole Variations

Ham and Swiss Breakfast Casserole

Swap the turkey sausage for 2 cups of diced ham. Replace cheddar with Swiss cheese. The ham does not need browning. Layer it directly over the potatoes for a milder, slightly sweet version.

Vegetarian Breakfast Casserole

Skip the sausage entirely. Add 2 cups of fresh spinach and 1 cup of sliced mushrooms to the skillet with the onion and pepper. The extra vegetables keep the casserole full and hearty without meat.

Spicy Southwest Breakfast Casserole

Add one diced jalapeño and 1/2 cup of canned green chiles to the sausage mixture. Use pepper jack cheese instead of cheddar. Top each slice with a spoonful of salsa after baking.

Bacon and Gruyère Breakfast Casserole

Cook 8 strips of thick-cut bacon until crisp. Crumble and layer over the potatoes. Swap cheddar for Gruyère. The nutty, rich cheese pairs well with smoky bacon.

Tips for the Best Breakfast Casserole

• I always assemble the night before and refrigerate. The potatoes absorb the egg mixture and bake up with better texture.
• Grease the dish generously. Stuck-on cheese is the hardest part to clean.
• Use a 9×13 inch dish for 8 servings. A smaller dish makes the casserole too thick in the center.
• Check doneness by pressing the center gently. It should feel firm with no visible liquid egg.
• Let it rest for a full 10 minutes. Cutting too early releases steam and makes the slices fall apart.
• Shred your own cheese from a block. Pre-shredded cheese melts unevenly and leaves a grainy top.

Make Ahead & Storage

This breakfast casserole stores in the fridge for up to four days in an airtight container. I slice it into individual portions before storing so each piece reheats evenly.

To freeze, wrap the unbaked assembled casserole tightly in plastic wrap and then foil. Freeze for up to two months. Thaw overnight in the fridge and bake as directed, adding 10 extra minutes. Reheat individual slices in the microwave for 90 seconds or in a 350 degree F oven for 12 minutes.

Common Questions

Can I make breakfast casserole the night before?

Yes. Assemble the full casserole, cover it tightly, and refrigerate overnight. The potatoes absorb the egg mixture and the flavors blend. Bake it straight from the fridge in the morning with 5 extra minutes of oven time.

What size dish do I need for breakfast casserole?

A 9×13 inch baking dish works best for this recipe. It holds all 8 servings in one even layer. A smaller dish makes the center too thick to cook through evenly.

Can I freeze baked breakfast casserole?

Yes. Let it cool completely, slice into portions, and wrap each piece in plastic wrap. Store in a freezer bag for up to two months. Reheat from frozen in the microwave for 2 minutes or in the oven at 350 degrees F for 15 minutes.

How do I know when breakfast casserole is done?

The center should feel firm when pressed lightly. The cheese on top turns golden with slightly crisp edges. If the center jiggles, bake for 5 more minutes and check again.

Can I use pork sausage instead of turkey?

Yes. Brown the pork sausage the same way and drain the extra fat before layering. Pork adds a richer, fattier flavor. Turkey keeps the casserole lighter.

This breakfast casserole from scratch is one recipe I come back to every holiday morning and busy weekend. Save it for your next brunch and make it the night before.