In a saucepan, combine brown sugar, vinegar, preserves, peaches, ginger and cinnamon stick. Simmer until the peaches are tender and the sauce has thickened, 25–30 minutes.
In the meantime, remove the ham from packaging and place in a roasting pan.
Once the sauce has thickened, pour half the glaze over the ham and allow to sink into the slices.
Fill the roasting pan with an inch of water and wrap pan with aluminum foil.
Place in the oven and bake until internal temperature reaches 140°F, about 10–15 minutes per pound.