Heat the butter in a large Dutch oven or stockpot. Sauté the onion over medium-high heat until soft, about 5 minutes. Add the garlic and continue to cook until fragrant, about 2 minutes.

Carefully stir in the pumpkin, stock, maple sugar, salt and nutmeg. Bring to a boil, then turn the heat to medium and simmer for 20-25 minutes, until the soup coats the back of a spoon. Off the heat, stir in the cream. Puree using an immersion or stand blender until very smooth.

Serve the soup in bowls and garnish with maple sugar.