Add all ingredients EXCEPT cornstarch in medium-sized sauce pot and whisk together.

Bring to a boil, then lower to medium-high heat until reduced to 1/3 in volume and slightly syrupy, about 10 minutes; then whisk in cornstarch until thickened. Set aside.

Thaw Duroc Boneless Country Ham in refrigerator for 26 to 28 hours.

Remove ham from packaging, place on a roasting rack in a roaster pan cut-side down, and allow ham to come to room temperature on counter over 1 hour.

Use 2 toothpicks to secure 1 pineapple ring on all 4 sides of ham and 1 on top.

Place in center rack of preheated 275 degrees oven, cover with aluminum foil.

Bake 90 to 100 minutes, brushing with glaze every 20 minutes; remove foil the last 20 minutes and increase heat to 325 degrees.

Internal temperature of ham should read 140F and ham should be nicely glazed and lacquered; serve with remaining glaze on the side.