1. Preheat oven to 350°.
2. Bring vermouth and honey to a boil in a small heavy saucepan; cook 16 minutes or until reduced to about 3/4 cup. Remove pan from heat.
3. Trim fat and rind from ham. Score outside of ham in a diamond pattern. Place ham on a broiler pan coated with cooking spray. Rub ham evenly with rosemary, pepper, and garlic. Bake at 350° for 1 1/2 hours. Brush ham with 1/4 cup vermouth mixture; cover loosely with foil. Bake an additional 45 minutes or until a thermometer inserted in center of ham registers 135°, basting with vermouth mixture every 15 minutes. Place ham on a serving platter; let stand 30 minutes before slicing