Grilled Cheese Breakfast Casserole

This grilled cheese breakfast casserole is your new lazy weekend breakfast dream. It blends crispy buttery grilled cheese sandwiches with a creamy, savory egg custard, making it perfect to prepare ahead and pop in the oven while you relax or get ready for the day.

I first made this on a chilly Sunday morning when I was craving indulgence without fuss. It quickly became a family favorite and a brunch staple.

Ingredients

• Eight slices of white or sourdough bread: buttered on one side for crispness and flavor. Choose fresh bread with a firm crust so it grills nicely without getting too soggy.
• One and a half cups shredded cheddar cheese: for melty, sharp cheesiness. I recommend sharp cheddar for balance but mild works too. Freshly shredded cheese melts better than pre-shredded.
• Six large eggs: for the custard base, delivering richness and structure. Always use fresh eggs for best taste and texture.
• One and a quarter cups whole milk: to keep the custard creamy and flavorful. Whole milk provides the best mouthfeel compared to lower fat options.
• Salt and black pepper: season the egg custard simply to complement the cheese without overpowering.
• Garlic powder: adds a subtle aromatic note that lifts the flavor. Use a good quality powder for the best taste.
• Smoked paprika: is optional but adds a gentle smoky depth that plays beautifully with the cheddar.
• Half a cup of cooked bacon or sausage crumbles: are optional but bring great protein and smoky saltiness. Use freshly cooked and drained meat to avoid excess grease.
• Butter or nonstick spray: to grease your pan and coat the bread, ensuring a golden crust that doesn’t stick.

Instructions

Preheat and Prepare Dish:

Preheat your oven to 350 degrees Fahrenheit and grease a 9 by 13 inch baking dish lightly with butter or nonstick spray. This prevents sticking and helps with even cooking.

Make Grilled Cheese Sandwiches:

Butter one side of each bread slice. Sandwich shredded cheddar between pairs of bread with the buttered sides facing out. Heat a skillet over medium heat and cook each sandwich for 2 to 3 minutes on each side until the bread is golden and cheese melted fully. Let cool slightly so the sandwiches firm up for easier handling. Cut each grilled sandwich into four quarters to fit nicely in the casserole dish.

Arrange in Baking Dish:

Place the grilled cheese quarters evenly in the prepared baking dish. Layer them as needed to fill the dish fully but without overcrowding.

Prepare Egg Mixture:

In a medium bowl whisk the eggs with the whole milk until smooth. Add salt, black pepper, garlic powder, and smoked paprika if using. Stir until fully combined. If you choose to add protein like bacon or sausage, fold it into the mix now.

Combine and Soak:

Pour the egg mixture evenly over the grilled cheese in the baking dish. Gently press the bread pieces down to help them soak up the custard, which creates a cohesive texture when baked.

Bake Covered:

Cover the casserole tightly with aluminum foil and bake for 25 minutes. This allows the egg custard to set gently and the flavors to blend.

Bake Uncovered:

Remove the foil and continue baking for another 10 to 15 minutes. The top should be puffed and golden while the center is fully set.

Rest and Serve:

Allow the casserole to rest for 5 minutes before cutting into squares. Serve warm to enjoy the melty cheese and custardy texture at its best.

Cheese is the star for me  I love how its gooey richness contrasts with the egg custard and buttery bread. One weekend, my siblings and I fought over the last piece at breakfast, so clearly it’s a hit.

Storage Tips

Store any leftovers covered tightly in the fridge for up to three days. Reheat gently in the oven or microwave until warmed through to retain that melty texture. Avoid overcooking when reheating to prevent dryness.

Ingredient Swaps

Swap white or sourdough bread for whole wheat or gluten-free bread depending on your dietary needs. Use your favorite cheese but keep it something that melts well like Monterey Jack or Swiss. Milk can be replaced with plant-based milk though the richness will be lessened.

Serving Ideas

Serve with fresh fruit or a side salad for a balanced breakfast or brunch. A small dollop of sour cream or a drizzle of hot sauce works surprisingly well to add brightness and depth.

Seasonal Twists

Add sautéed mushrooms or spinach into the egg mixture for green freshness and extra nutrients. Seasonal herbs like chives or parsley sprinkled on top before baking add brightness and color. In colder months, swap the bacon for cooked chorizo to introduce warmth and spice.

Enjoy this make-ahead breakfast that brings comfort and convenience to your weekend mornings.

Frequently Asked Recipe Questions

→ What type of bread works best for this dish?

White or sourdough bread is ideal as it holds up well during grilling and soaking in the egg mixture without becoming too soggy.

→ Can I use different cheeses?

Cheddar offers great flavor and meltability, but you can experiment with mozzarella or gouda for unique twists.

→ Is it necessary to grill the sandwiches before baking?

Grilling creates a crispy, golden crust that prevents the bread from getting mushy and adds a toasty flavor layer.

→ How do I ensure the casserole sets properly?

Covering the dish while baking helps the egg custard set gently. Removing the cover later browns the top and finishes cooking.

→ Can I add proteins like bacon or sausage?

Yes, cooked bacon or sausage crumbles can be folded into the egg mixture before pouring to boost savory flavors.