In a large stock pot or Dutch oven, heat olive oil over medium-high heat.
Saute the onion and leek about 3 minutes, or until softened.
Add sweet potatoes, vegetable and chicken stock, salt, and cinnamon stick. Bring to a boil.
Cover and reduce heat and simmer about 40 minutes, until sweet potatoes are fork tender. Discard the cinnamon stick.
Process the soup in batches with your blender (use caution when blending hot liquids!!!) or with your immersion blender, until thick and creamy.
Return liquid to pot and stir in cream, vinegar, nutmeg, clove, cayenne, and pepper. Heat through, but do not let boil.
For the Maple Cream:
In the bowl of your electric mixer fitted with the paddle attachment, whisk cream on high until soft peaks form.
Slowly add maple syrup and salt. Whip until just combined being careful not to over whip (dry peaks).
Serve soup with dollops of cream on top.
Notes
For leftovers sake, i just stirring the remaining cream into the soup letting it melt evenly. When reheating, microwave on low power stirring every 40 seconds until heated through.