Bring a large pot of salted water to a rolling boil. Add the fettuccine and cook until al dente, about 8-10 minutes. Reserve ½ cup of pasta water, then drain the pasta.

In a large skillet, melt the unsalted butter over medium heat. Add minced garlic and sauté until fragrant, about 1-2 minutes.

Stir in pumpkin puree and heavy cream into the skillet. Heat the mixture for 3-5 minutes, stirring until smooth.

Gradually whisk in the grated Parmesan cheese until melted. Adjust sauce consistency with reserved pasta water if necessary.

Toss the drained fettuccine into the skillet with the sauce, coat evenly, and adjust seasoning with salt and pepper.

Plate the pasta warm, garnishing with chopped parsley or sage and pumpkin seeds if using. Serve immediately.