Make-Ahead Bacon and Cheddar Breakfast Casserole

Name: Make-Ahead Bacon and Cheddar Breakfast Casserole
Prep time: 30 min
Cook time: 50 min
Total time: 3 h 30 min
Yield: 12 servings
Cuisine: Italian
Ingredients: 1 tablespoon unsalted butter, softened, for greasing the baking dish; 1 pound day-old French or Italian bread, cut into 1-inch cubes, about 10 cups; 1 pound thick-cut bacon, cut crosswise into 1/2-inch pieces; 1 medium yellow onion, finely chopped, about 1 cup; 12 ounces sharp cheddar cheese, freshly shredded, about 3 cups, divided; 3 tablespoons thinly sliced fresh chives, divided; 2 teaspoons fresh thyme leaves; 10 large eggs; 3 cups whole milk; 2 teaspoons Dijon mustard; 3/4 teaspoon kosher salt; 1/2 teaspoon garlic powder; 1/2 teaspoon freshly ground black pepper

Imperial August 8, 2026August 8, 2026

Quick Recipe Version (TL;DR)

Yield: 12 servings
Prep Time: 30 minutes
Cook Time: 50 minutes
Total Time: 3 hours 30 minutes, including 2 hours chilling and 10 minutes resting

Quick Ingredients

1 tablespoon unsalted butter, for the baking dish
1 pound day-old French or Italian bread, cut into 1-inch cubes, about 10 cups
1 pound thick-cut bacon, chopped
1 medium yellow onion, finely chopped, about 1 cup
12 ounces sharp cheddar cheese, shredded, about 3 cups
3 tablespoons chopped fresh chives, divided
2 teaspoons fresh thyme leaves
10 large eggs
3 cups whole milk
2 teaspoons Dijon mustard
3/4 teaspoon kosher salt
1/2 teaspoon garlic powder
1/2 teaspoon freshly ground black pepper

Do This

1. Butter a 9-by-13-inch baking dish and place the bread cubes in a large bowl.
2. Cook the bacon over medium heat for 10 minutes. Reserve 2 tablespoons, then cook the onion in 1 tablespoon bacon fat for 5 minutes.
3. Layer the bread, remaining bacon, onion, 2 1/2 cups cheddar, 2 tablespoons chives, and thyme in the baking dish.
4. Whisk the eggs, milk, Dijon, salt, garlic powder, and pepper; pour evenly over the bread and press gently to moisten.
5. Cover and refrigerate for exactly 2 hours, or make it up to 12 hours ahead.
6. Bake at 350°F for 30 minutes covered, then add the reserved bacon and 1/2 cup cheddar and bake uncovered for 20 minutes.
7. Rest for 10 minutes, garnish with the remaining chives, and serve warm.

Why You’ll Love This Recipe

It combines crisp bacon, sharp cheddar, tender bread, and savory herbs in every bite.
The casserole can be assembled the night before, making busy mornings much easier.
One 9-by-13-inch pan generously feeds a family or brunch crowd.
The golden, cheesy top contrasts beautifully with the soft, custardy center.

Grocery List

Produce: 1 medium yellow onion, 1 small bunch fresh chives, 1 small package fresh thyme
Meat: 1 pound thick-cut bacon
Dairy: 10 large eggs, 3 cups whole milk, 12 ounces sharp cheddar cheese, 1 tablespoon unsalted butter
Bakery: 1 one-pound loaf day-old French or Italian bread
Pantry: Dijon mustard, kosher salt, garlic powder, black pepper

Full Ingredients

For the Bread, Bacon, and Cheese Layers

1 tablespoon unsalted butter, softened, for greasing the baking dish
1 pound day-old French or Italian bread, cut into 1-inch cubes, about 10 cups
1 pound thick-cut bacon, cut crosswise into 1/2-inch pieces
1 medium yellow onion, finely chopped, about 1 cup
12 ounces sharp cheddar cheese, freshly shredded, about 3 cups, divided
3 tablespoons thinly sliced fresh chives, divided
2 teaspoons fresh thyme leaves

For the Egg Custard

10 large eggs
3 cups whole milk
2 teaspoons Dijon mustard
3/4 teaspoon kosher salt
1/2 teaspoon garlic powder
1/2 teaspoon freshly ground black pepper

Make-Ahead Bacon and Cheddar Breakfast Casserole – Closeup

Step-by-Step Instructions

Step 1: Prepare the baking dish and bread

Coat the bottom and sides of a 9-by-13-inch baking dish with 1 tablespoon softened butter. Cut the day-old bread into uniform 1-inch cubes; you should have about 10 cups. Place the bread cubes in a large mixing bowl. Slightly dry bread is ideal because it absorbs the egg custard without becoming pasty.

Step 2: Crisp the bacon and soften the onion

Place the chopped bacon in a large skillet and set it over medium heat. Cook for 10 minutes, stirring every 2 minutes, until the fat has rendered and the bacon is crisp. Transfer the bacon to a paper-towel-lined plate with a slotted spoon. Reserve 2 tablespoons of bacon for the topping.

Leave 1 tablespoon of bacon fat in the skillet and carefully discard the rest. Add the chopped onion and cook over medium heat for 5 minutes, stirring occasionally, until softened and lightly golden. Remove the skillet from the heat.

Step 3: Build the savory bread layers

Arrange half of the bread cubes, about 5 cups, in the prepared baking dish. Top with half of the cooked onion, half of the bacon that was not reserved, 1 1/4 cups shredded cheddar, 1 tablespoon chives, and 1 teaspoon thyme. Repeat with the remaining bread, onion, non-reserved bacon, another 1 1/4 cups cheddar, 1 tablespoon chives, and the remaining 1 teaspoon thyme. Reserve the final 1/2 cup cheddar and remaining 1 tablespoon chives for finishing.

Step 4: Mix and add the egg custard

In a large bowl, whisk the eggs for 1 minute, until the yolks and whites are completely blended. Add the whole milk, Dijon mustard, kosher salt, garlic powder, and black pepper. Whisk for another 1 minute, until smooth and evenly combined.

Slowly pour the custard over the casserole, moving around the dish so all areas are evenly moistened. Use clean hands or the back of a large spoon to press the bread gently into the liquid. Do not compact it firmly; the goal is simply to help the top cubes absorb some custard.

Step 5: Cover and chill

Cover the baking dish tightly with foil and refrigerate for at least 2 hours. For an easy make-ahead breakfast, refrigerate the assembled casserole for up to 12 hours. This resting period allows the bread to absorb the seasoned egg mixture and creates an evenly tender, custardy interior.

Step 6: Bake until puffed and golden

Remove the casserole from the refrigerator and let it stand at room temperature for 20 minutes while the oven preheats to 350°F. Keep the dish covered with foil and bake on the center rack for 30 minutes.

Carefully remove the foil. Sprinkle the reserved 1/2 cup cheddar and 2 tablespoons bacon over the top. Return the casserole to the oven and bake uncovered for exactly 20 minutes, until the cheese is melted, the top is golden, and the center reaches 160°F on an instant-read thermometer. The center should look set rather than wet, although a slight jiggle is normal.

Step 7: Rest, garnish, and serve

Set the baking dish on a heat-safe surface and let the casserole rest for 10 minutes. Resting helps the custard finish setting and makes the casserole easier to cut. Sprinkle with the reserved 1 tablespoon chives, slice into 12 portions, and serve warm.

Pro Tips

Use day-old bread: Slightly stale French or Italian bread absorbs the custard while maintaining its structure. If your bread is fresh, spread the cubes on a baking sheet and dry them in a 300°F oven for 15 minutes, then cool before assembling.
Shred the cheese yourself: Freshly shredded cheddar melts more smoothly than packaged shredded cheese, which often contains anti-caking agents.
Choose sharp cheddar: Its bold flavor remains noticeable after it is combined with the bread, milk, and eggs.
Do not skip the resting time: Ten minutes of resting keeps each serving intact while preserving the soft, custardy center.
Check the center: For the most reliable result, insert an instant-read thermometer into the middle and confirm that it has reached 160°F.

Variations

Vegetable cheddar casserole: Replace half of the bacon with 2 cups sliced mushrooms and 1 cup diced red bell pepper. Sauté the vegetables with the onion until their moisture has cooked away.
Spicy bacon casserole: Add 1 finely chopped jalapeño with the onion and whisk 1/4 teaspoon cayenne pepper into the custard. Pepper Jack can replace 1 cup of the cheddar.
Smoky herb casserole: Replace 1 cup of cheddar with smoked Gouda and substitute 2 teaspoons chopped fresh rosemary for the thyme.

Storage & Make-Ahead

To make the casserole ahead, assemble it through Step 5, cover tightly, and refrigerate for 2 to 12 hours before baking. Store cooked leftovers in an airtight container in the refrigerator for up to 4 days. Reheat individual portions in the microwave for 60 to 90 seconds, or cover several portions and warm them in a 325°F oven for 20 minutes. To freeze, wrap cooled individual portions tightly and place them in a freezer-safe container for up to 2 months. Thaw overnight in the refrigerator before reheating. Refrigerate leftovers within 2 hours of serving.

Nutrition (per serving)