This creamy vegan butternut squash pasta sauce recipe calls for store-bought butternut squash puree, so it's easy to prepare. Cashews add richness and creaminess to this dairy-free sauce, and giving the sauce a final whir in the blender gives it a silky smooth texture. The optional nutritional yeast adds a mild parmesan-like flavor. Serve the sauce over your favorite pasta and add a simple salad for a comforting and healthy fall dinner.