Bring a large pot of salted water to a rolling boil. Add pasta and cook until al dente, about 8-10 minutes. Reserve 1-2 cups of pasta water before draining.

In a skillet, heat olive oil and half of the butter over medium-low heat. Add minced garlic and black pepper. Sauté for 1-2 minutes until fragrant.

Stir in pumpkin puree and 1 cup of reserved pasta water with nutmeg. Simmer for 3-5 minutes to thicken the sauce.

Add drained pasta to the skillet with the sauce. Toss gently and stir in parmesan and pecorino cheese until melted. Adjust consistency with reserved pasta water if needed.

Serve immediately, garnished with additional parmesan, cracked black pepper, and chopped parsley.