Combine the pumpkin, curry powder, and brown sugar in a pot over medium heat.
Whisk in the coconut milk a little at a time until smooth.
Add the vegetable broth a little at a time, until you reach your desired consistency. You may not use the full cup. Season with salt and pepper, to taste.
Simmer the soup for 10 minutes to allow flavors to develop, stirring occasionally.
Taste to adjust seasonings and serve hot, garnished with pumpkin seeds, if desired.