Prepare Your Baking Dish: Begin by greasing a 9x13 inch baking dish with butter or cooking spray to ensure an easy release after baking.
Whisk Wet Ingredients Together: In a large mixing bowl, combine eggs, milk, half and half, brown sugar, pumpkin puree, pumpkin pie spice, and vanilla extract until well blended.
Add Bread Cubes: Gently fold in cubed day-old French bread into the egg mixture ensuring each piece is fully coated with that creamy goodness.
Create Topping Mixture: In another bowl, mix packed brown sugar, flour, additional pumpkin pie spice, and salt before cutting in softened butter until crumbly.
Assemble Casserole: Pour the bread mixture into your prepared baking dish and evenly sprinkle the topping over it before covering with foil.
Bake & Serve: Bake in a preheated oven at 350°F (175°C) for about 45 minutes or until golden brown; serve warm drizzled with maple syrup for an unforgettable breakfast experience.