Butter sides and bottom of a 9x13 pan and set aside. Place bread cubes in a large mixing bowl.

In a separate bowl, whisk eggs together and add pumpkin puree. Whisk until smooth. Mix in pumpkin spice egg nog. Add brown sugar, pumpkin pie spice, cinnamon, salt, and vanilla and whisk until combined. Pour mixture over bread cubes and very gently toss until covered. Let sit for 2-3 minutes and then toss again, making sure all bread cubes get covered in some of the egg mixture. Place entire mixture in prepared 9x13 inch pan, cover, and refrigerate overnight.

In a small bowl, combine brown sugar, white sugar, flour, pumpkin pie spice, and cinnamon, Either grate butter with a large-hole cheese grater, or cut it into small chunks, and use fingers to crumble mixture together. Cover, and place crumb topping in fridge overnight.

In the morning, take french toast pan out and set at room temperature while you preheat the oven to 350 degrees. Uncover pan and sprinkle crumb topping evenly over the top. Bake for 45-55 minutes, until puffed and golden all over. (Mine usually takes closer to 55 minutes). Remove and let cool for 10 minutes or so and then cut into squares and serve.

Serve with softened or melted butter, 100% real maple syrup, and sweetened whipped cream sprinkled with pumpkin pie spice.