Preheat your oven to 350 degrees Fahrenheit and spray a 9 by 13 pan with cooking spray.
In a large bowl, whisk the eggs, milk, heavy cream, sugar, and vanilla together.
8 whole eggs, 1 1/2 cups milk, 1/2 cup heavy cream, 1/2 cup granulated sugar, 2 teaspoons vanilla
Whisk in the cranberry sauce. Add the bread, making sure that it is completely coated.
14 ounces whole cranberry sauce, 16 ounces Italian bread
Using two forks or a pastry cutter, combine the brown sugar, cold butter, and oats. 1 cup light brown sugar, 1/2 cup unsalted butter, 1/2 cup oats
Pour the bread and egg mixture into the prepared pan. Top with the topping and put it into the oven for about 50 minutes or until the casserole puffs up and starts to pull away from the edges of the pan. You may need to cover the casserole in the last 10 minutes of baking to prevent over-browning.