Heat the large soup pot over medium heat, then add the olive oil or butter. Once melted, add the diced onion and cook for about 3-4 minutes until it becomes translucent and fragrant.
Add the minced garlic to the pot and cook for another 30 seconds until fragrant, stirring constantly to prevent burning.
Toss in the chopped apples and cook for 5 minutes, stirring occasionally, until they start to soften and release their aroma.
Pour in the apple cider and sprinkle in the cinnamon, chili powder, salt, and black pepper. Stir well, bringing the mixture to a gentle simmer.
Reduce the heat to low, cover the pot, and let the soup simmer for about 20-25 minutes, or until the apples are very tender and fully cooked.
Once cooked, remove the pot from heat. Use an immersion blender directly in the pot to blend the soup until smooth and velvety, or carefully transfer to a blender in batches.
If the soup is too thick, stir in a splash more apple cider or warm water to reach your desired consistency. Taste and adjust seasoning if needed.
Serve the hot soup in bowls, garnished with a sprinkle of chili powder or cinnamon for extra flavor and visual appeal.
