Preheat the oven to 350 degrees. Spoon the pumpkin puree into a food processor and add the eggs, cream, cheese, salt, and pepper. Process for 10 to 15 seconds to combine. Coat a 6-cup gratin dish with the butter. Fill the dish with the pumpkin mixture. Sprinkle the Parmesan cheese on top and bake for 35 to 45 minutes, until set and lightly browned on top. Serve.