Preheat oven to 350°F. Let ham stand at room temperature 30 minutes. Gather ingredients.
Place ham in a large roasting pan; fill pan with water to a depth of ½ an inch. Cover pan with aluminum foil. Bake in preheated oven until an instant-read thermometer inserted into thickest portion of meat registers 120°F, about 2 hours, basting ham every 30 minutes with accumulated juices in pan.
Meanwhile, stir together maple syrup, brown sugar, bourbon, ginger, and cinnamon in a medium saucepan; bring to a boil over medium-high. Cook, stirring occasionally, until thickened, 6 to 8 minutes. Remove from heat. Cover to keep warm, and set aside.
Remove ham from oven; remove and discard foil. Increase oven temperature to 400°F. Using a pastry brush, glaze ham with ⅓ cup maple mixture; set aside remaining glaze.
Return ham to oven, and bake at 400°F until top is lightly caramelized a thermometer inserted into thickest portion of meat registers 145°F, about 30 minutes, brushing with remaining glaze every 10 minutes. Remove from oven.
Transfer ham to a platter; let rest 15 minutes. Serve.
Notes
The ham is fully cooked when the internal temperature reaches 145°F. Letting the ham stand at room temperature for 30 minutes before roasting ensures even heating.