In a large pot, heat 2 tablespoons of olive oil over medium heat. Add one chopped yellow onion, sautéing for 5-7 minutes until it turns soft and translucent. Stir in 3 minced garlic cloves and 1 tablespoon of freshly grated ginger, cooking for an additional minute.

Add 1 teaspoon of ground cinnamon, ¼ teaspoon of ground nutmeg, and a pinch of red pepper flakes to the pot. Stir these spices for about 30 seconds until fragrant.

Pour in 4 cups of vegetable broth, stirring to combine. Incorporate 3 peeled and diced sweet potatoes and 1 chopped apple, ensuring they are mostly submerged in the broth.

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

Using an immersion blender, blend the soup until smooth and creamy. If using a regular blender, allow the soup to cool slightly and blend in batches.

Stir in ½ cup of heavy cream or coconut milk. Season with salt and black pepper to taste, adjusting as desired. Heat gently if necessary.

Ladle the hot soup into bowls and garnish with optional toppings. Serve with crusty bread or a light salad.