In a heavy stock pot, melt 2 tablespoons butter over low heat.
Add 3/4 cup finely diced onion and minced garlic cloves.
Stir in ground cinnamon and ground nutmeg,
Stir and cook over low heat until onions are translucent, but do not brown.
Add 1/2 cup marsala wine and 4 cups chicken stock.
Turn up the heat and bring to a boil.
Turn the heat down and simmer on low for 15 minutes.
Stir in canned pumpkin and maple syrup.
Cook for a few more minutes until thoroughly heated.
Process in a food processor or use an immersion blender until velvety smooth.
For best flavor, refrigerate in a glass container for a few hours or overnight to allow flavors to meld.
Return pumpkin soup to stock pot and add heavy cream, salt and pepper.
Continue stirring and slowly heat until steaming. DO NOT BOIL or soup may separate.
Serve steaming hot.
Optional: garnish with a dollop of sour cream or fresh herb sprigs.