I can't remember where I first found this recipe, and I've modified it quite a bit over the years. This is what I usually make for Christmas; we're going over to friends' tomorrow, so I made it tonight instead, and I thought I'd write it down finally.
1 can frozen orange juice concentrate
12-oz bottle real maple syrup
powdered ginger root
1. Preheat oven to 325 degrees.
2. Empty the can of o.j. concentrate into a saucepan, and melt it over medium-low heat.
3. While you're thawing the o.j., add maple syrup to taste. I use 8-10 ounces.
4. When the o.j. is fully melted, and it and the maple syrup are blended nicely (don't let it boil), add about a tablespoon of mustard and a tablespoon of ginger. Mix well. Add pepper to taste.
5. Place the ham in a glass baking dish. With a sharp knife, score the surface of the ham. I usually take a fork and poke a bunch of holes in the surface after scoring it with the knife. The idea is to make it really easy for the glaze to sink into the meat. Poke a meat thermometer in so that the tip is in the middle of the ham.
6. Pour the orange juice-maple syrup mixture over the ham, making sure the surface is entirely coated. Depending on how big your baking pan is, you could have as much as an inch of glaze pooling around the base of the ham. That's okay.
7. Bake the ham until it reaches an internal temperature of at least 145 degrees. Depending on how big the ham is this could take anywhere from an hour to two hours. I bake the ham uncovered because this helps the glaze condense and concentrate; the glaze, in turn, keeps the ham from drying out, so you don't need the foil that some recipes call for. At least in my experience.
8. Every half hour or so during baking I take the ham out and spoon more of the mixture from the bottom of the pan over the ham.
9. When the ham is done, transfer it to a serving dish, spoon as much of the glaze over it as you like, and pour the rest into a bowl to use as a sauce as needed. The maple, o.j., and spices will be enriched with ham drippings, and the result will be awesome.