1. Cut peaches into halves and remove pit.
2. In a bowl, mix the balsamic vinegar, maple syrup, black pepper, vanilla and apricot preserve.
3. Place the peaches on grill flat side down.
4. Baste the peaches with this mixture and grill for 3 minutes.
5. Flip the peaches and fill in the pits with the remaining mixture. Grill for 3 minutes.
6. Continue with one more round of basting as the peaches get grilled.
7. Remove from grill, plate and serve as dessert.