Preheat your oven to 425 degrees F, and spray two 6" cast iron pans (or similar sized baking dishes) with a nonstick spray. Set aside.
In a medium bowl, whisk together the flour, pumpkin pie spice and fine sea salt. In a separate larger bowl, whisk together the eggs, heavy cream, pumpkin puree, maple syrup and melted butter. Fold the dry ingredients into the wet until just moistened. Do not overmix. Divide the batter between the two pans. Place them in the oven and bake for 15 minutes.
While the pumpkin spice dutch babies are baking, prepare your cinnamon streusel. In a medium bowl, whisk together the flour, brown sugar, cinnamon and salt. With a pastry cutter or your fingers, work the cubed butter into the dry ingredients. Mixing until the mixture represents coarse crumbles. Set aside or place in the refrigerator while the pumpkin spice dutch babies continue baking.
After 15 minutes, carefully remove the dutch babies from the oven and split the cinnamon streusel between both pans. Place them back in the oven and continue baking for an additional 10 minutes or until the streusel is lightly golden.
Remove from heat and let stand for about 3 minutes before serving. Dust with confectioner's sugar if desired and enjoy!