1 loaf thick-cut brioche or challah bread (about 1 pound), cut into 1-inch cubes
8 large eggs
2 cups whole milk
½ cup heavy cream
¾ cup granulated sugar
2 tbsp. vanilla extract
1 tsp. ground cinnamon
½ tsp. ground nutmeg
¼ tsp. salt
Butter for greasing the pan
Streusel Topping
½ cup all-purpose flour
½ cup packed brown sugar
1 tsp. ground cinnamon
¼ tsp. salt
½ cup (1 stick) cold unsalted butter, cut into small pieces
Instructions
Prepare the Casserole (Night Before)
Grease a 9x13-inch baking dish generously with butter.
Spread the bread cubes evenly in the prepared dish.
In a large bowl, whisk together eggs, milk, heavy cream, sugar, vanilla, cinnamon, nutmeg, and salt until well combined.
Pour the custard mixture evenly over the bread cubes. Press the bread down gently with a spatula so it absorbs the liquid.
Cover tightly with plastic wrap and refrigerate overnight (or at least 4 hours).
Make the Streusel and Bake
Preheat oven to 350°F (175°C). Remove the casserole from the refrigerator while the oven heats.
In a medium bowl, combine flour, brown sugar, cinnamon, and salt. Cut in the cold butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
Sprinkle the streusel topping evenly over the casserole.
Bake uncovered for 45-50 minutes, until the top is golden brown and the center is set (a knife inserted in the center should come out clean).
Let cool for 10 minutes before serving. Serve warm with maple syrup, powdered sugar, or fresh berries.
Tips:
Day-old bread works best — it soaks up the custard without falling apart. If your bread is fresh, cut it into cubes and let them sit out for a few hours to dry slightly.
The overnight soak is key — don't skip it. The bread needs time to fully absorb the custard for the best texture.
If the top browns too quickly, tent loosely with foil for the last 10-15 minutes.
Leftovers reheat well in the microwave or in the oven at 325°F covered with foil.
Variations:
Fold in 1 cup of blueberries or sliced strawberries before refrigerating
Add 4 oz. softened cream cheese, cubed and scattered between the bread layers
Swap brioche for cinnamon raisin bread for extra sweetness
Top with chopped pecans or walnuts along with the streusel
For a lighter version, substitute half-and-half for the heavy cream