• Place the ham with its inner plastic or foil covering intact in the kitchen sink. Completely cover the ham with hot tap water. Let stand for 45 minutes. Drain the water, cover it again with hot tap. Let stand for another 45 minutes.
• Adjust oven rack to lowest position and preheat oven to 250°F. Drain water covering the ham. Unwrap ham and remove the plastic disk covering the bone. Discard all packaging and disk.
• Place the ham in an oven bag with the cut side on the bottom of the bag. Gather the top snugly around the ham, tie the bag at the top and trim excess gathered plastic at the top. In a large roasting pan, set ham cut-side down. Using a scissors, cut 4 slits in the top of the bag below the tie.
• Bake ham for 1 to 1 ½ hours (about 12 minutes per pound) or until the center registers 110 degrees Fahrenheit when tested with an instant-read thermometer.

To Make Maple-Orange Glaze:

• Meanwhile, in a small saucepan combine all of the ingredients. Cook over medium heat, stirring occasionally, 5 to 7 minutes or until mixture is thick, syrupy, and reduced to 1 cup. Set aside.
• Remove ham from oven. Increase oven temperature to 350°F. Using a scissors, cut open the oven bag and roll back sides to expose ham. Brush ham with one-third of the prepared glaze.
• Return the ham to the oven about 10 minutes more or until glaze becomes sticky and the internal temperature reaches 130°F.
• Remove ham from oven, transfer to cutting board. Brush on another third of the glaze. Tent ham loosely with foil and let rest 15 minutes.
• Meanwhile, heat remaining third of glaze with 4 to 6 tablespoons of ham juices until it becomes a thick but fluid sauce. Transfer sauce to a serving bowl. Carve ham.
• Serve ham, passing the sauce at the table.