Preheat the oven to 400 degrees F. Line a baking sheet with foil.
Toss the butternut squash with the 2 teaspoons olive oil, ½ teaspoon salt, and sage and a dusting of Aleppo pepper. Roast the squash for 25 minutes or until fork tender.
Drizzle and swirl the remaining olive oil in a heavy stockpot set over medium heat. Saute the onion, celery, and salt for 8 to 10 minutes or until translucent. Add the squash to the pot, tossing together. Pour in the chicken stock. Cover and simmer for 10 minutes or until the butternut squash is fork tender.
Pour a portion of the soup into the blender with apple slices, removing the cap, and covering the top with a towel. Puree the soup in batches.
Garnish with a swirl of creme fraiche and perhaps a few fried sage leaves, if desired. (To fry them, line a plate with a paper towel. Heat a slick of olive oil in a skillet over medium low heat. Once shimmering, add the extra sage leaves, lightly frying them until they take on a little bit of color. Drain them on the paper towel before placing them atop of the soup as a garnish.