For the Stuffed Shells
26 jumbo pasta shells
¾ cup Parmigiano Reggiano, finely grated
8 ounces whole-milk mozzarella cheese, shredded
12 ounces whole-milk ricotta cheese
¾ teaspoon fresh rosemary, finely minced
Pinch of ground nutmeg
Salt, to taste
Freshly ground black pepper, to taste
For the Pumpkin Cream Sauce
4 tablespoons butter
3 garlic cloves, minced
¾ teaspoon ground nutmeg
15 ounces pumpkin puree
1½ cups half-and-half
¾ cup Parmigiano Reggiano, finely grated
1½ teaspoons fresh rosemary, finely minced
½ teaspoon kosher salt
Freshly ground black pepper, to taste
Extra shredded mozzarella, optional, for topping