Bring a large pot of water to boil.
In a large skillet, heat butter (or oil) over medium heat until melted and hot. Add minced garlic and sauté until golden and fragrant, about 2-3 minutes, stirring occasionally. Whisk in the pumpkin puree and heavy cream (or coco cream). Bring to a simmer, reduce heat to medium-low, then let cook 15-20 minutes to thicken, whisking occasionally.
While the pumpkin sauce is thickening, cook your fettuccine according to the package instructions using the water that is hopefully boiling from step one. Drain the pasta then set aside (pro tip: throw a little oil or butter in with the drained noodles so they don’t stick to each other or the pot/colander).
Once the pumpkin sauce from step two has thickened, stir in the parmesan cheese (or nutritional yeast) plus a healthy pinch of sea salt and black pepper. Stir in the cooked fettuccine then toss to coat and mix everything together.
Divide pumpkin fettuccine Alfredo into bowls, top with extra parmesan cheese plus fresh chopped rosemary if you so desire then ENJOY.