Preheat oven to 325°F and arrange a rack in the lower third portion of oven.
In a medium pot over low heat, add the orange juice, maple syrup, bourbon, mustard, brown sugar, and lemon juice. Stirring occasionally until the glaze reaches a simmer.
In a separate small bowl add the cornstarch and whisk in the cold water until completely mixed. Over low heat, whisk the cornstarch mixture into the glaze continue whisking until glaze has thicken, remove from heat.
Remove the ham from the package and pat dry if too wet. Place ham in a roasting pan, flat side down, so the fatty side is facing up. Gently score the ham in a criss-cross pattern. Using 3/4 cup of glaze to brush all over the ham.
Cover ham loosely with aluminum foil to prevent drying out or burning. Bake ham for 1 hour. Remove roasting pan from the oven, discard the foil from the top and sides of the ham. Using the remaining glaze, brush ham every 6-7 minutes and bake for additional 20 minutes (glaze approximately 3 times during this step).
Remove roasting pan from oven and place ham on large cutting board. Let cool for 10 minutes before carving.