Optional Garnish:
To make the spider web pattern on the soup. Place vegan sour cream in either a piping bag, bottle with a pour spout or plastic sandwich bag with the tip cut off. Drizzle cream in a spiral. Use a tooth pick or something similar. Starting with the centre drag the toothpick through the cream to the edge of the bowl. Repeat around the spiral until you are satisfied with the design.
Find it online: https://susancooksvegan.com/purple-sweet-potato-soup/