Spray a 9x13" baking dish with non stick cooking spray. Set aside.
In a large mixing bowl add the pumpkin, milk, sugar, eggs, and spice. Whisk together until evenly combined.
Pour this batter into the prepared baking dish, and use a spatula to spread it out evenly.
To a separate mixing bowl add the cake mix, nuts, and melted butter. Stir them together until evenly combined & the mixture's crumbly.
Spread the topping mixture evenly out over the baking dish.
Bake the cobbler at 350° for 40-50 minutes. It's done when the edges are golden brown and crusty/crispy and the center is soft.
Remove the dish from the oven, and let it rest for a full 10-15 minutes.
Serve it with an ice cream scoop, scooping it into bowls while still warm.
Scoops of vanilla ice cream and a caramel syrup drizzle are a delicious way to finish this dessert off.