Bring a pot of water to a boil and cook the spaghetti/pasta according to the instructions on the package.
Heat the olive oil in the pan on medium heat and add the onion. Cook, stirring frequently, for 4 to 5 minutes, or until translucent and tender. Add the garlic and sage and stir to combine. Cook for 2 to 3 minutes, stirring frequently. Add the wine to deglaze the pan and stir. Cook for 2 minutes and remove from heat and let cool slightly.
Put the pumpkin, plant-based milk, onion and sage mixture, and pasta water in a high powered blender and blend until smooth and creamy. If you have a Blendtec blender use the Whole Foods – Soup setting for best results.
Wipe the pan that you cooked the onions in to remove any pieces of onion or garlic that may be left. Pour the cream sauce in the pan and salt and pepper. Bring to a low boil on medium-low heat. Add more pasta water if you want a thinner sauce.
Drain the pasta and add to the pan. Stir to coat the pasta. Plate and sprinkle any or all of the toppings over the pasta.
Store in a covered container in the refrigerator for up to 3 days. Stir in a little plant-based milk to make the sauce creamy when reheating.