Grease a 9" x 13" casserole dish. Cut or tear the French bread into roughly 1" pieces and place them evenly in the dish.
1 pound French bread
In a large bowl, whisk together the eggs, heavy cream, milk, light brown sugar, vanilla, cinnamon, and salt until fully combined. Pour the mixture evenly over the bread chunks, ensuring all the pieces are coated. Sprinkle the chopped pecans over the top. Cover the dish and refrigerate overnight, or let it sit at room temperature for an hour if baking the same day.
8 large eggs, 1 cup heavy cream, 2 cups milk, ⅓ cup light brown sugar, 1 tablespoon vanilla extract, 2 teaspoon ground cinnamon, ½ teaspoon salt, ½ cup pecans
In a small bowl, combine the brown sugar, cinnamon, nutmeg, and chopped pecans. Cut the cold butter into the mixture until crumbly. Cover and refrigerate the topping until you're ready to bake.
½ cup brown sugar, 1 teaspoon cinnamon, ¼ teaspoon nutmeg, 2 ounces pecans, 2 tablespoons butter
When ready to bake, preheat the oven to 350°F (175°C). Remove the casserole and the topping from the fridge, allowing them to sit at room temperature for 30 minutes. Sprinkle the topping evenly over the casserole. Bake for approximately 45 minutes, or until the top is golden brown and the casserole is set.
Let the casserole rest for 10 minutes before serving. Serve with warm maple syrup, whipped cream, or fresh berries.