Croissant Breakfast Casserole Recipe

Learn how to make this homemade Croissant Breakfast Casserole – the best make-ahead brunch option for feeding a crowd! This easy baking recipe transforms day-old croissants into a decadent, custardy delight with crispy edges and a soft center. Perfect for holiday mornings or weekend entertaining.

Difficulty:

Beginner

Prep Time:

20 mins

Cook Time:

45 mins

Serves:

8 servings

Ingredients

<ul class="ingredients-main-list"> <li class="ingredients-single-item">6 large day-old croissants (about 300g)</li> <li class="ingredients-single-item">200g bacon, chopped</li> <li class="ingredients-single-item">1 medium onion, finely diced</li> <li class="ingredients-single-item">150g Gruyère cheese, grated (or Emmental)</li> <li class="ingredients-single-item">100g cheddar cheese, grated</li> <li class="ingredients-single-item">6 large eggs</li> <li class="ingredients-single-item">350ml whole milk</li> <li class="ingredients-single-item">120ml double cream</li> <li class="ingredients-single-item">1 tbsp Dijon mustard</li> <li class="ingredients-single-item">2 tbsp fresh chives, chopped</li> <li class="ingredients-single-item">1 tbsp fresh thyme leaves</li> <li class="ingredients-single-item">½ tsp salt</li> <li class="ingredients-single-item">¼ tsp freshly ground black pepper</li> <li class="ingredients-single-item">¼ tsp grated nutmeg</li> </ul>

Nutrition Facts (per serving)

🍽️ Serving Size:

🔥 Calories:

🥑 Fat:

🧈 Saturated Fat:

🍞 Carbohydrates:

🍭 Sugar:

🍗 Protein:

🫀 Cholesterol:

🧂 Sodium:

Equipment

<ul class="equipment-main-list"> <li class="equipment-single-item">23 x 33cm (9 x 13-inch) baking dish</li> <li class="equipment-single-item">Non-stick frying pan</li> <li class="equipment-single-item">Mixing bowls</li> <li class="equipment-single-item">Whisk</li> </ul>

Directions

<ol class="no-list-style"> <li class="MethodStepper"> <h4 class="step-title">Step 1</h4> Begin by greasing your 23 x 33cm baking dish with butter or non-stick cooking spray. This prevents the casserole from sticking and makes serving much easier. </li> <li class="MethodStepper"> <h4 class="step-title">Step 2</h4> In a frying pan over medium heat, cook the chopped bacon until it's just crisp, about 5-6 minutes. Using a slotted spoon, transfer the bacon to a paper towel-lined plate, leaving about 1 tablespoon of the rendered fat in the pan. </li> <li class="MethodStepper"> <h4 class="step-title">Step 3</h4> Add the diced onion to the bacon fat and sauté until translucent and softened, about 4-5 minutes. Remove from heat and let cool slightly. The residual bacon flavor will infuse into the onions, adding depth to your casserole. </li> <li class="MethodStepper"> <h4 class="step-title">Step 4</h4> Tear the croissants into bite-sized pieces (about 3-4cm chunks) and spread half of them evenly in the prepared baking dish. Don't make the pieces too small – you want them to maintain some structure after soaking. </li> <li class="MethodStepper"> <h4 class="step-title">Step 5</h4> Sprinkle half the cooked bacon, half the sautéed onions and half of each cheese over the croissant layer. Then add the remaining croissant pieces and top with the remaining bacon, onions, and cheeses. This layering technique ensures every bite has a good distribution of flavors. </li> <li class="MethodStepper"> <h4 class="step-title">Step 6</h4> In a large bowl, whisk together the eggs, milk, cream, Dijon mustard, herbs, salt, pepper, and nutmeg until well combined. The mustard adds a subtle tanginess that balances the richness of the custard, while the nutmeg enhances the savory notes. </li> <li class="MethodStepper"> <h4 class="step-title">Step 7</h4> Slowly pour the egg mixture over the croissant layers, making sure to cover all the pieces. Press down gently with a spatula to ensure the croissants begin absorbing the custard. Let the casserole sit for at least 30 minutes at room temperature, or cover and refrigerate overnight. This resting period is crucial as it allows the croissants to fully absorb the custard mixture. </li> <li class="MethodStepper"> <h4 class="step-title">Step 8</h4> When ready to bake, preheat your oven to 180°C (350°F). If the casserole was refrigerated overnight, let it sit at room temperature for about 30 minutes while the oven heats. This helps ensure even baking. </li> <li class="MethodStepper"> <h4 class="step-title">Step 9</h4> Bake the casserole uncovered for 45-50 minutes, until it's puffed, golden brown, and the center is set but still slightly jiggly. If the top starts browning too quickly, loosely cover with aluminum foil. The casserole will continue to set as it cools. </li> <li class="MethodStepper"> <h4 class="step-title">Step 10</h4> Remove from the oven and let rest for 10-15 minutes before serving. This resting period allows the custard to set further and makes it easier to cut clean portions. The casserole will deflate slightly as it cools – this is perfectly normal. </li> <li class="MethodStepper"> <h4 class="step-title">Step 11</h4> Garnish with additional fresh herbs if desired, and serve warm. The casserole offers a delightful contrast between the crispy golden top and the soft, custardy interior – a truly comforting breakfast treat! </li> </ol>

FAQs

Find answers to your most pressing questions about this delicious recipe right here.

What ingredients are used in Croissant Breakfast Casserole Recipe?

This indulgent breakfast bake combines day-old croissants, bacon, onion, Gruyère and cheddar cheeses, eggs, milk, double cream, Dijon mustard, fresh herbs (chives and thyme), plus seasonings including salt, pepper and nutmeg for a rich, savoury casserole.

How to cook Croissant Breakfast Casserole at home?

Learn how to cook Croissant Breakfast Casserole by layering torn croissants with bacon, onions and cheese in a baking dish, then pouring over a seasoned custard mixture of eggs, milk and cream. Let it soak (preferably overnight), then bake at 180°C for 45-50 minutes until golden and puffy with a slight wobble in the centre.

Can I prepare a breakfast casserole the night before?

Absolutely! In fact, overnight preparation is ideal for breakfast casseroles. Assembling everything the night before allows the croissants to fully absorb the custard mixture, resulting in a more flavourful, evenly textured dish with that perfect balance of crispy top and custardy interior.

What's the best way to prevent a breakfast casserole from becoming soggy?

Using day-old or slightly stale croissants is key as they absorb moisture without becoming soggy. Ensure your croissant pieces aren't too small, maintain the recommended egg-to-bread ratio, and don't skip the resting period. The golden bake time of 45-50 minutes creates that perfect crispy top.

What can I substitute for Gruyère cheese in a breakfast bake?

If Gruyère isn't available, Emmental works brilliantly as mentioned in the recipe. Other excellent substitutes include Comté, Swiss cheese, fontina, or a good quality white cheddar. Each offers different nuances, but all provide that desirable meltability and savoury depth.

Want to try something else in ...