Preheat oven to 400 degrees F. Spray a 9×9 inch (or similar size) baking pan with cooking spray.
Cook pasta in a large pot of salted water, until al dente, drain and return to the pot.
While the pasta is cooking, combine the evaporated milk, pumpkin puree, eggs, smoked paprika, salt, pepper and cayenne and mix until combined. Pour the mixture into the pot with the pasta and stir until combined. Continue cooking over medium-high heat, stirring occasionally, for about 3-4 minutes, or until the sauce comes to a simmer and thickens slightly.
Remove pan from heat and stir in about 6 ounces of the shredded cheddar and the Parmesan until melted and evenly-distributed.
Pour the pasta into the prepared baking pan. Then top with the remaining cheese and breadcrumbs.
Bake for 20-25 minutes, or until the cheese is bubbling and the breadcrumbs are toasted. Remove and serve immediately.