Cook the Gnocchi:
Bring a pot of salted water to a boil and cook the gnocchi until they float (about 2–3 minutes). Drain and set aside.
Prepare the Pumpkin Cream Sauce:
Melt butter in a skillet. Add garlic and sauté. Stir in pumpkin purée, then whisk in heavy cream until smooth. Season with sage, thyme, nutmeg, salt, and pepper.
Combine:
Add cooked gnocchi to the sauce and gently toss to coat evenly.
Assemble the Bake:
Transfer the gnocchi mixture to a greased baking dish. Top with mozzarella and Parmesan.
Bake:
Bake at 375°F (190°C) for 20–25 minutes until the cheese is melted and golden. Broil for 2–3 minutes for a crisp top.
Serve:
Let rest for 5 minutes before serving.