Make the marinade: Get out a mixing bowl and add the brown sugar, brandy, water, cinnamon, and vanilla extract to it. Use either a fork or a whisk to combine these ingredients until the sugar has dissolved. Set this aside.

Marinate the peaches: Get out a flat walled dish (like a casserole dish or pie pan) and place each peach half into it. Pour the marinade over the peaches and let them sit in your fridge for at least 30 minutes or up to 2 hours. Then flip each peach over and let them marinate for an additional 30 minutes to 2 hours. 1 hour total will be enough, but marinating them for longer will give them more flavor, so if you got the time, do it!

Take the marinated peaches out of your fridge and preheat your grill to high.

Grill the peaches: Place each peach half on your hot grill cut side down. Let them cook for 3 to 5 minutes or until they have grill marks. Then flip each peach over and let them cook for an additional 3 to 5 minutes or until they feel nice and tender.

Serve your grilled peaches immediately and enjoy!