Heat oven to 325ºF.
Mix sugar, syrup and mustard. Place ham, fat-side up, in roasting pan. Score ham if desired; cover with foil. Bake 1 hour.
Remove foil. Brush ham with 1/3 of the glaze.
Bake, uncovered, 1 hour or until heated through (160ºF), brushing with remaining glaze every 20 min. If ham begins to brown too quickly, cover loosely with foil.
Remove ham from oven; transfer to cutting board. Tent with foil; let stand 15 min before carving.
To score the ham, make 1/4-inch-deep parallel cuts, about 1 inch apart, in top surface of ham. Make additional scores at right angles to form diamond shapes. Cloves can be inserted into the ham where the lines cross for a show-stopping presentation.