I've spent years perfecting this pumpkin breakfast casserole!It's a great make ahead recipe for anytime during the fall months, or Thanksgiving morning. Check my notes above this recipe card for info on ingredient swaps and storing leftovers.
Add the half and half, eggs, coffee, maple syrup, pumpkin puree, salt, 1 teaspoon pumpkin pie spice, and vanilla extract to a large mixing bowl and whisk until well combined. Set aside.
Arrange the bread pieces in the bottom of a greased 9x13-inch baking pan.
Pour the egg mixture evenly over the top of the bread. Set aside.
Make the crumble topping. Add the flour, brown sugar, remaining teaspoon pumpkin pie spice, and butter to a separate small bowl and work the butter in with your hands until the entire mixture is moistened.
Sprinkle the crumble topping evenly over the top of the casserole.
Cover the casserole tightly with plastic wrap and place in the refrigerator overnight.
When you are ready to bake the casserole, preheat the oven to 350 degrees Fahrenheit.
Replace the plastic wrap on the casserole with aluminum foil and bake in the preheated oven for 30 minutes. Remove the foil and bake for an additional 15 minutes or until the top is golden brown.