Preheat oven to 325°F.
Let the ham sit: Remove the ham from its packaging. Let it rest for 1 hour at room temperature so it's not so cold, which helps it cook more evenly.
The set-up: Grab a big roasting pan with a rack. Place the ham on top of the rack, flat side down. You can put a sheet of foil under the ham if you'd like (poke a few holes on the foil so the juices flow down). Add water to the bottom of the pan, about ½ inch. Wrap the pan tightly in aluminum foil.
Bake: Cook the ham the oven for about 1½ hours. Tip: The trapped steam inside will keep the ham tender and moist.
Make the glaze: About 20 minutes before the ham is done, make the glaze. In a saucepan over medium heat, combine all the glaze ingredients and stir to combine. Adjust the flavors to taste as needed. Reduce to low heat, and simmer for about 8 minutes until it’s a bit thickened, stirring often to make sure it doesn't burn. Set aside.
Increase oven temperature to 400°F. Remove the ham from the oven and remove the foil.
Brush with the glaze: If needed, reheat the glaze to loosen it up so that it's easier to brush. Brush the ham with glaze, including in between the slices. Then return to the oven for about 6 minutes, uncovered. Repeat this step about 2 more times until caramelized and slightly charred around the edges.
Let it rest: Remove them ham from the oven and let sit for 15-20 minutes before serving. Slice and serve. Enjoy!