Prepare Ham: Score the surface of the ham in a diamond pattern. If using, insert cloves at the intersections.

Make the Glaze: Combine brown sugar, honey or maple syrup, mustard, vinegar, and cinnamon in a saucepan. Simmer until smooth and slightly thickened.

Bake: Place ham cut-side down in a roasting pan. Cover loosely with foil and bake for about 1.5 to 2.5 hours, depending on size.

Glaze It: Brush with glaze during the final 30–40 minutes of baking, basting every 10–15 minutes.

Rest & Serve: Let the ham rest 15 minutes before carving. Garnish if desired.