1Peel pineapple, then quarter lengthwise. Cut out core, then cut each quarter lengthwise into 4 pieces (for a total of 16).
2Scrape seeds from vanilla bean into a 12-inch heavy skillet with tip of a paring knife, then add pod, wine, Grand Marnier, brown sugar, cinnamon stick, bay leaf, cloves, and a large pinch of salt. Bring to a boil, stirring until sugar has dissolved.
3Add pineapple to wine mixture and return to a boil. Remove from heat. Cool pineapple in liquid, about 1 hour. Transfer pineapple with a slotted spoon to a 4-sided sheet pan, then boil liquid until reduced to about 2/3 cup, about 35 minutes.
5Sprinkle pineapple with granulated sugar, then broil 3 to 4 inches from heat until slightly caramelized and lightly charred in spots, 10 to 15 minutes (watch carefully and remove any pineapple that colors more quickly). Serve drizzled with syrup.
Pineapple can be poached and liquid reduced 1 day ahead and chilled separately. Sprinkle with sugar and broil before serving.