A tender, juicy spiral sliced ham coated in a buttery brown sugar and Dijon mustard mixture, baked with pineapple juice and fresh oranges, and finished with a sticky, caramelized brown sugar glaze.
Preheat oven to 325°F. Line a roasting pan with aluminum foil. Pour 1 cup pineapple juice into the bottom and add the sliced orange. Insert a roasting rack.
Remove the ham from its packaging, including all plastic pieces and the bone guard. Place the ham on the roasting rack with the large, flat side facing down.
In a bowl, combine the brown sugar, softened butter, and Dijon mustard. Generously coat the ham, gently working the mixture between the spiral slices.
Cover the roasting pan tightly with aluminum foil, sealing around the edges. Bake at 325°F. After approximately 1 hour and 20 minutes, begin checking the internal temperature in the thickest part of the ham, avoiding the bone. Continue baking, covered, until the ham reaches 140°F, or the reheating temperature specified on the packaging.
While the ham bakes, combine all glaze ingredients in a wide skillet. Bring to a steady simmer over medium heat, uncovered. Stir frequently until reduced and syrupy, approximately 10–15 minutes or longer as needed. Remove from heat and allow to cool slightly.
Once the ham reaches 140°F, remove the foil and brush with half of the glaze.
Return to the oven uncovered for 10–15 minutes, or until the glaze becomes beautifully caramelized.
Remove the ham from the oven and brush with the remaining glaze, gently working some between the slices.
Arrange fresh rosemary and roasted orange slices around the edge of a serving platter. Place the ham in the center and serve.
