Lightly grease a 9x13" casserole dish and place cubed bread in an even layer in dish. Set aside.
Whisk together the eggs, milk, heavy cream, sugar, maple syrup and vanilla extract in a large bowl until mixture is pale yellow. Pour mixture over the bread, trying to coat each piece of bread.
In a separate small bowl combine the topping ingredients and use a fork or pastry cutter to combine, until mixture is coarse and crumbly. Sprinkle mixture evenly over bread. Wrap tightly with plastic wrap and place in fridge overnight (or for at least 4 hours).
In the Morning:
Preheat oven to 350 degrees F. Unwrap casserole dish and bake for 50 to 60 minutes, until middle of casserole is set. If the top begins to brown too much, lightly lay a piece of foil over the top and continue baking until finished.
Let sit for a few minutes before slicing and enjoying!
If desired, you can drizzle a powdered sugar glaze over the top of the warm casserole. Combine 1 cup of powdered sugar with 1 tbsp of milk and whisk to combine. Drizzle over casserole.