Place a large, heavy-bottomed pot over medium heat.

Add olive oil to the pot.

Add the diced onion, apple, and a pinch of kosher salt to the pot.

Saute the mixture for approximately 5 minutes, or until the onions become soft and translucent.

Pour the chicken stock, apple cider, thyme, and pepper into the pot.

Bring the mixture to a boil for one minute.

Add the pumpkin puree to the pot and stir until smooth.

Use an immersion blender to puree the soup until smooth.

Stir in the cream and brown sugar until the sugar is completely dissolved.

Simmer the soup for about ten minutes, or until it is heated through.

Serve the soup warm.