Thoroughly coat a 9×13 inch baking pan with cooking spray. Evenly spread the bread cubes in the pan.In a large bowl, whisk together eggs, milk, pumpkin puree, vanilla, maple syrup, and pumpkin pie spice until well combined. Pour over bread and push down with a spoon or your hands until it’s all soaked and mostly covered. Cover with saran wrap or lid and refrigerate overnight.In the morning, uncover the pan and preheat oven to 350 degrees.In a small bowl mix together the brown sugar, nuts, and cinnamon. Sprinkle over the top of the bread mixture and bake for approximately 45 minutes or until golden brown and no longer wet.Serve immediately with maple syrup or honey.