Overnight Croissant Breakfast Casserole — Easy Breakfast Casserole for Busy Mornings

I still remember the first time I made this Overnight Croissant Breakfast Casserole for a sleepy holiday morning. I had a pile of day-old croissants, guests arriving soon, and zero time to fuss. The next day, the kitchen filled with buttery, eggy aroma and everyone reached for seconds — it felt like a warm, flaky hug. That cozy success is why I keep this recipe in heavy rotation: it’s forgiving, feeds a crowd, and turns leftover croissants into something special. If you love simple make-ahead breakfasts or want a decadent weekend treat, this dish is a keeper. For more quick morning inspiration, check out these breakfast ideas.

Who is this recipe for?

• This recipe is perfect for busy parents, brunch hosts, or anyone who loves an easy, make-ahead breakfast that feels special.

Core ingredients overview:

• This casserole combines 6 croissants (torn into pieces), 6 eggs, 2 cups milk, 1 cup shredded cheese (cheddar or Swiss), 1/2 cup diced ham or cooked sausage (optional), 1/2 cup chopped bell peppers (optional), salt and pepper, and fresh herbs for garnish. The result is a rich, custardy breakfast casserole that’s customizable and comforting — a great companion to other make-ahead dishes like high-protein overnight oats for balanced mornings.

Tools & Ingredients:

Tools (you will need)

• 9×13-inch baking dish — holds the casserole and bakes evenly.
• Mixing bowl — for whisking eggs and milk.
• Whisk or fork — to blend the custard smoothly.
• Measuring cups and spoons — for accurate ratios.
• Knife and cutting board — to chop ham and peppers.
• Spatula or spoon — to distribute ingredients evenly.
• Plastic wrap or foil — to cover the dish overnight.
• Refrigerator and oven — for chilling and baking.

Ingredients (with short benefits)

• 6 croissants, torn into pieces — flaky, buttery base that soaks up the custard beautifully.
• 6 eggs — provide structure, protein, and a creamy custard texture.
• 2 cups milk — creates the custardy filling and keeps the bake moist.
• 1 cup shredded cheese (cheddar or Swiss) — adds melty, savory flavor and golden top.
• 1/2 cup diced ham or cooked sausage (optional) — boosts protein and adds savory depth.
• 1/2 cup chopped bell peppers (optional) — bring color, crunch, and vitamin C.
• Salt and pepper to taste — essential seasoning to enhance all flavors.
• Fresh herbs for garnish (optional) — brighten the dish and add fresh aroma.

Instructions:

1. Grease a 9×13-inch baking dish and evenly distribute the torn croissant pieces in the bottom.
2. In a bowl, whisk together the 6 eggs and 2 cups milk. Season with salt and pepper.
3. Pour the egg mixture over the croissants. Add the 1 cup shredded cheese, 1/2 cup diced ham or cooked sausage (if using), and 1/2 cup chopped bell peppers (if using) on top.
4. Cover the dish tightly with plastic wrap or foil and refrigerate overnight.
5. The next morning, preheat the oven to 350°F (175°C).
6. Bake uncovered for about 30–40 minutes, or until the eggs are set and the top is golden brown.
7. Garnish with fresh herbs if desired and serve warm.

FAQ:
Q: Can I freeze this recipe?
A: Yes. Bake the casserole fully, let it cool, then wrap tightly and freeze for up to 2 months. Thaw overnight in the fridge and reheat in a 350°F (175°C) oven until warmed through.

Q: What can I use instead of croissants?
A: Stale brioche, challah, or even thick sandwich bread work well. Croissants give the richest flavor, but other soft breads will soak up the custard nicely.

Q: Can I make this dairy-free or use a milk alternative?
A: Yes. Substitute oat milk or almond milk and use a dairy-free cheese to make a lactose-free version, but texture and flavor will be slightly different.

Q: Is there a vegetarian version?
A: Absolutely. Omit the ham or sausage and add sautéed mushrooms, spinach, or extra peppers for a satisfying vegetarian casserole.

Tips & Tricks:

• Use slightly stale croissants if you can — they absorb the custard more evenly and help prevent a soggy bottom.
• Don’t overfill the dish with add-ins; keep a good bread-to-custard ratio so the middle sets properly.
• Let the casserole rest 5–10 minutes after baking before cutting — it firms up and slices more cleanly.
• For extra texture, sprinkle a little extra cheese on top during the last 5 minutes of baking to get a bubbly, golden finish. For another casserole-style idea, see this chicken casserole with noodles.

Enjoy this warm, easy breakfast with family and friends — it’s perfect for slow mornings and busy brunches. Always add

tag after Directions.

Conclusion

For more variations and inspiration, you might enjoy this detailed Overnight Breakfast Bake – Croissant Breakfast Bake, a gourmet take at Overnight Croissant Breakfast Casserole – Bring Gourmet to your …, or a bacon-forward twist like Overnight Cheesy Bacon Croissant Breakfast Casserole.