Bacon & Egg Croissant Bake: The Easiest Way to Use Up Leftover Croissants

I found myself staring at a trio of leftover Costco croissants the other morning, wondering how to use them up before they went totally stale. They were still soft enough to work with but clearly not fresh enough to enjoy as-is. Add in a few slices of pre-cooked bacon I had in the fridge, some extra sharp cheddar (also from Costco, naturally), and it felt like the universe was pointing me toward a savory croissant bake.

I love making croissant bakes for a lot of reasons — mainly because they’re forgiving. You can throw in whatever you have on hand, and they almost always come out tasting like you planned it. This particular version turned out so well that I had to write it down. It’s got crispy bacon, sharp cheddar, creamy cottage cheese, and a surprise pop of flavor from spinach pesto. Plus, it reheats like a dream in the toaster oven.

Bacon & Egg Croissant Bake

Ingredients: 

• 3 croissants, preferably a day old, but fresh is fine
• 3 eggs
• ½ cup milk
• 3-4 slices of bacon
• ½ small onion, finely diced
• ½ cup sharp cheddar cheese, shredded
• 1 tbsp creme fraiche (can substitute with sour cream)
• ½ cup cottage cheese
• 1-2 tbsp spinach pesto
• ½ tsp salt
• ½ tsp pepper
• ¼ tsp garlic powder
• ½ tbsp dijon mustard
• Butter for greasing the baking dish 

Instructions:

1. Preheat oven to 350℉ and grease an 8’ x 8’ baking dish. 
2. Cook the bacon until crispy, then crumble it into pieces. Remove half of the bacon grease, then in the same pan, sauté the diced onion until soft and slightly golden. 
3. Tear the croissants into bite-sized pieces and place them evenly in the baking dish
4. In a bowl (or blender if you want a smoother consistency), whisk together the eggs, milk, crème fraiche, cottage cheese, salt, pepper, mustard, and garlic powder until mostly smooth. If you are whisking instead of blending, it’s okay if the cottage cheese stays a little chunky — it adds texture! 
5. Stir in the shredded cheddar cheese, cooked bacon, and sautéed onions into the egg mixture. Fold to combine. 
6. Pour the egg mixture evenly over the torn croissants, gently pressing down so the croissants soak up the liquid. 
7. Dot small spoonfuls of spinach pesto across the top and let the mixture soak into the croissant for 5 minutes before putting into your pre-heated oven.
8. Bake for 25-30 minutes, or until the casserole is puffed up, golden, and set in the middle (no jiggle!). 
9. Let cool for a few minutes before serving. Optional, serve with arugula in a light lemon and olive oil dressing.

Looking for something sweet instead of savory? Check out this Berry Croissant Bake >

Notes & Swaps

• No sharp cheddar? Gruyère, Swiss, or even mozzarella will work in a pinch.
• No crème fraîche? Sour cream is a perfect sub.
• Want to add greens? Toss in some sautéed spinach, kale, or even arugula.
• Leftovers? Skip the microwave and reheat slices in a toaster oven or conventional oven to keep that croissant crispness.

This recipe is perfect for a lazy weekend breakfast, a make-ahead brunch, or even a cozy breakfast-for-dinner situation. It feels indulgent, but it’s mostly made from things you probably already have in your kitchen.

Let me know if you make it — and what fun add-ins you use!