1 1/2 cups packed dark-brown sugar
1/4 cup brandy or bourbon
2 tablespoons grainy mustard
1 bone-in half ham (about 6 pounds), fully cooked
In a small saucepan, combine sugar, brandy, and mustard. Bring to a boil over medium; cook until glaze is thick and syrupy, 3 minutes. (To store, refrigerate, up to 2 days. Reheat before using.)
Preheat oven to 275 degrees. Using a sharp knife, cut off hard rind from ham (if any); score the fat in a diamond pattern. Place ham, cut side down, in a roasting pan or on a rimmed baking sheet and cover tightly with foil. Bake until an instant-read thermometer inserted in thickest part reads 145, 1 1/2 hours.
Brush ham generously with glaze, making sure to coat all exposed areas. Increase oven temperature to 350 degrees and bake, uncovered, until glaze is sticky and ham is browned, about 35 minutes. Serve warm or at room temperature.