Prepare your base. Heat oil in a large pot over medium heat. Add the diced onion and cook until translucent, about 3-4 minutes. Add the minced garlic and cook for another minute until fragrant.
Incorporate the spices. Add the grated ginger and turmeric (or ground versions) to the pot and stir continuously for 30 seconds to toast the spices and release their flavors. This quick toasting step dramatically enhances the aromatic qualities of the soup.
Add the pumpkin and seasonings. Add the cubed pumpkin, cumin, and cayenne (if using) to the pot. Stir well to coat the pumpkin with the spices and cook for about 2 minutes.
Pour in the liquid. Add the vegetable broth and bring the mixture to a boil. Once boiling, reduce the heat to low, cover, and simmer for about 20 minutes, or until the pumpkin is very tender when pierced with a fork.
Blend until smooth. Remove the pot from heat and use an immersion blender to puree the soup until completely smooth. Alternatively, carefully transfer the soup in batches to a regular blender (be cautious with hot liquid).
Add richness with coconut milk. Return the pot to low heat and stir in the coconut milk and maple syrup (if using). Heat gently without boiling to preserve the coconut milk’s texture.
Season to perfection. Taste and adjust seasoning with salt and pepper. If the soup is too thick, add a little more broth or water to reach your desired consistency.
Serve with finesse. Ladle the hot soup into bowls and garnish with fresh cilantro leaves and/or toasted pumpkin seeds. Add a squeeze of lime juice just before serving for a bright finish.