Overnight Croissant Breakfast Casserole – The Ultimate Make-Ahead Morning Delight

When mornings feel rushed but you still crave a cozy, homemade breakfast, this Overnight Croissant Breakfast Casserole swoops in to save the day. Imagine golden, buttery croissants baked in a creamy egg custard with savory sausage, smoky ham, and layers of gooey melted cheese. It’s the kind of hearty, indulgent dish that turns an ordinary morning into a brunch-worthy event.

This casserole is everything we love about breakfast – comforting, rich, and easy to make ahead. With just a few simple ingredients, you can prep it the night before and wake up to a meal that smells like a dream.

Why You’ll Love This Recipe

• Perfect for busy mornings: Assemble it the night before and just bake in the morning.
• Versatile: You can swap or add your favorite breakfast meats and veggies.
• Crowd-pleasing: Ideal for family brunches, holidays, or meal prepping for the week.
• Comfort food at its finest: Buttery croissants soak up the custard and bake into pure perfection.

Ingredients

🧈 For the Casserole

• 6 large croissants, preferably a day old, torn into large chunks
• 1 cup cooked breakfast sausage, crumbled
• ½ cup diced ham
• 1 cup shredded cheddar cheese
• ½ cup shredded mozzarella cheese
• 6 large eggs
• 1 ½ cups whole milk
• ½ cup heavy cream
• ½ teaspoon salt
• ¼ teaspoon black pepper
• ¼ teaspoon garlic powder (optional)
• 2 tablespoons chopped parsley (plus more for garnish)
• Butter or non-stick spray for greasing

Instructions

1. Prepare the Croissants
   Slice or tear the croissants into large chunks and lightly toast them if they’re very soft. This helps them soak the custard without getting soggy.
2. Cook the Meats
   In a skillet, cook the sausage until browned and crumbly. Drain excess fat and set aside. Dice ham into small cubes if not pre-diced.
3. Assemble the Base
   Lightly grease a 9×13-inch baking dish. Layer half the croissant pieces in the bottom. Sprinkle over half the sausage, ham, and both cheeses.
4. Add the Second Layer
   Add the remaining croissant pieces and top with the remaining meats and cheese.
5. Make the Egg Mixture
   In a large mixing bowl, whisk together eggs, milk, cream, salt, pepper, and garlic powder. Pour this evenly over the croissants, pressing gently so they soak up the liquid.
6. Chill Overnight
   Cover tightly with plastic wrap and refrigerate overnight (or at least 6 hours). This allows the croissants to absorb the custard.
7. Bake It Fresh
   Preheat the oven to 350°F (175°C). Remove casserole from the fridge while preheating. Bake uncovered for 40–45 minutes, until the top is golden brown and puffed.
8. Garnish and Serve
   Let it rest for 10 minutes before serving. Sprinkle with fresh parsley and a bit of extra cheese if desired.

Overnight Croissant Breakfast Casserole

A buttery, cheesy, make-ahead breakfast bake with flaky croissants, sausage, ham, and eggs – perfect for busy mornings or holiday brunch.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr 5 minutes mins

Servings: 8 slices

Course: Breakfast, Brunch

Cuisine: American

Calories: 410

Ingredients Equipment Method Notes

Ingredients

  

Casserole

• 6 large croissants day-old, torn into chunks
• 1 cup cooked breakfast sausage crumbled
• 0.5 cup diced ham
• 1 cup shredded cheddar cheese
• 0.5 cup shredded mozzarella cheese
• 6 large eggs
• 1.5 cups whole milk
• 0.5 cup heavy cream
• 0.5 tsp salt
• 0.25 tsp black pepper
• 0.25 tsp garlic powder optional
• 2 tbsp chopped parsley plus extra for garnish

Equipment

• Mixing bowls
• Whisk
• 9×13 inch baking dish
• Skillet

Method

 

1. Lightly grease a 9×13-inch baking dish.
2. Layer half the croissant pieces, sausage, ham, and cheeses in the dish.
3. Repeat with remaining ingredients.
4. In a large bowl, whisk together eggs, milk, cream, salt, pepper, and garlic powder.
5. Pour egg mixture evenly over croissants, pressing gently to soak.
6. Cover and refrigerate overnight (or at least 6 hours).
7. Preheat oven to 350°F (175°C). Bake uncovered 40–45 minutes until golden and set.
8. Cool 10 minutes, garnish with parsley, and serve warm.

Notes

You can prepare and bake the same day if needed—just let it rest at least 30 minutes before baking.

Tips for Success

• Use day-old croissants. Fresh ones can be too soft and won’t absorb the custard as well.
• Try different cheeses. Swiss, Monterey Jack, or Gruyère all work beautifully.
• Add veggies. Spinach, bell peppers, or mushrooms bring a burst of color and flavor.
• Make mini versions. Use muffin tins for individual breakfast cups – perfect for meal prep!

Variations

• Sweet & Savory: Add caramelized onions and a drizzle of maple syrup for a breakfast twist.
• Vegetarian Option: Skip the meats and add sautéed spinach, tomatoes, and feta.
• Spicy Version: Use pepper jack cheese and add diced jalapeños.
• Holiday Special: Mix in leftover turkey or ham from festive dinners.

Serving Suggestions

Pair your Overnight Croissant Breakfast Casserole with a side of fresh fruit salad, crispy hash browns, or a simple green salad for a complete meal. For brunch gatherings, serve with coffee, orange juice, or mimosas.

Why It Works Overnight

The magic happens while it chills in the fridge. The croissants absorb the creamy egg mixture, allowing the flavors to meld beautifully. When baked, you get a contrast of textures – crisp, buttery tops and custardy centers. It’s the perfect balance of soft and crunchy.

Storage & Reheating

• Refrigerate: Store leftovers in an airtight container for up to 4 days.
• Freeze: You can freeze portions for up to 2 months. Reheat in the oven for best texture.
• Reheat: Warm in a 350°F oven for 10–15 minutes until heated through.

Fun Fact

Did you know croissants originated in Austria, not France? The French perfected them, of course—but combining their buttery layers with American-style casseroles gives us the best of both worlds.

Final Thoughts

Whether you’re feeding a crowd or just want a warm, luxurious breakfast with your morning coffee, this Overnight Croissant Breakfast Casserole delivers. It’s a fuss-free recipe with gourmet flavor, easy prep, and ultimate comfort baked in.