Preheat the oven: Heat your oven to 425°F (220°C). Line a large baking sheet with parchment paper if desired.
Season the ingredients: Add the pumpkin, sliced apples, chopped onion, and whole garlic cloves to the baking sheet. Drizzle with olive oil and sprinkle with cinnamon, nutmeg, ginger, salt, and black pepper. Toss well to coat everything evenly.
Roast: Spread the mixture into a single layer. Roast for 30–35 minutes, stirring halfway through, until the pumpkin is tender and the apples are soft and lightly caramelized.
Blend: Remove the baking sheet from the oven and let the roasted ingredients cool slightly. Transfer everything to a blender or food processor. Add the vegetable broth and blend until completely smooth.
Adjust the consistency: If the soup is thicker than you prefer, add a little more vegetable broth and blend again until it reaches your desired consistency.
Add the cream: Pour the blended soup into a large pot. Stir in the heavy cream or full-fat coconut milk.
Warm gently: Heat over medium-low heat for 5–7 minutes, stirring occasionally. Avoid bringing the soup to a boil so the creamy texture stays smooth.
Season and serve: Taste the creamy roasted apple pumpkin soup and adjust the salt, pepper, cinnamon, nutmeg, or ginger if needed. Ladle into bowls and garnish with toasted pumpkin seeds and a swirl of cream, if desired. Serve warm.