Spray a 9×13-inch pan with cooking spray. Preheat your oven to 350 degrees F.

In a large bowl, mix the eggs, milk, heavy cream, sugar, ½ cup brown sugar, vanilla, 2 teaspoons cinnamon, and nutmeg until well blended.

Chop the bread into ¾-inch to 1-inch cubes and toss well in the egg mixture.

In a small bowl or food processor, combine flour, remaining brown sugar, cinnamon, and salt. Cut in the cold butter until crumbly.

Pour the bread and egg mixture into the prepared pan. Cover evenly with the brown sugar-butter topping, and bake for 45-50 minutes.