Prepare almond-vanilla oil for garnish. Place oil and vanilla bean in a small saucepan over medium heat. Bring to a temperature of 190 degrees, using a candy thermometer. Remove from the heat and allow to cool to room temperature. Cover and set aside to infuse at room temperature for 24 hours.
Prepare the soup. In a medium stockpot, melt the butter over medium-low heat. Add the shallots and sweat for 2-3 minutes. Add the parsnip, celery root, and 4 sprigs of rosemary. Continue to sweat for 5-6 minutes. Add the pear, and continue cooking for 4-5 minutes. Add the white wine, increase heat to high, and reduce by half - to about 1 cup of liquid. Add the stock and bring to a boil, reduce to a simmer and cook for 45 minutes. Remove soup from the heat, and stir in the cream. Remove the rosemary, and transfer the soup to a blender. Blend on high speed until smooth. Place remaining 2 rosemary sprigs in a chinois or fine mesh strainer, and strain soup over it. Season to taste with the cider vinegar and salt, and reheat gently. Serve soup drizzled with almond-vanilla oil.