Prepare the ingredients. Finely chop the yellow onion and grate the garlic cloves. Strip the leaves from the thyme sprigs until you have about 2 tablespoons.
Sauté the aromatics. Warm 2 tablespoons of olive oil in a medium saucepan over medium heat until it shimmers. Add the chopped onion, diced sweet potatoes, and garlic, cooking for 3 to 4 minutes until they release their aroma.
Incorporate the pumpkin and spices. Stir in the thyme, the pumpkin purée, kosher salt, ground cumin, black pepper, ground ginger, and cayenne pepper. Continue to cook on medium-low heat until the mixture is heated through and fragrant, approximately 5 minutes.
Add the vegetable broth. Pour in 2 cups of low-sodium vegetable broth, stirring constantly. Let it cook for 3 to 4 minutes until the mixture begins to bubble.
Finish with maple syrup and coconut milk. Lower the heat, then stir in the maple syrup and coconut milk. Bring to a quick boil to get the coconut flavor out of the soup, while stirring frequently. For a smoother texture, you can blend the soup using an immersion blender or transfer it to a blender until it reaches your desired consistency.
Garnish and serve. Ladle the soup into bowls and serve warm, topped with toasted pumpkin seeds, a sprinkle of flaky salt, fresh thyme leaves, and additional black pepper if desired.