Heat the olive oil in a large pot over medium heat until shimmering.

Sauté the chopped onion for 5-7 minutes until soft and translucent. Add minced garlic and grated ginger, stirring until fragrant.

Add ground cinnamon, ground nutmeg, and red pepper flakes. Cook for 30 seconds until well combined.

Pour in vegetable broth, sweet potatoes, and apple. Ensure they are mostly submerged, adding more broth if needed.

Bring to a boil, then reduce heat to low, cover, and let simmer for 20-25 minutes until sweet potatoes are fork-tender.

Blend the soup until smooth using an immersion blender or in batches with a traditional blender.

Stir in heavy cream or coconut milk and season with salt and pepper. Heat gently for 2-3 minutes.

Ladle into bowls and garnish with toppings of your choice.