Place ham in a large baking dish, cover with aluminum foil and bake for 30 minutes.
In a small mixing bowl, whisk together real maple syrup, brown sugar, coarse-grain mustard, fresh rosemary, Kosher salt and allspice.
Remove and uncover. Baste between each ham slice and over the top with all basting liquid. If your ham slices are having trouble staying up see my tip above for tying your ham.
Return to oven, uncovered for 45 minutes.
Remove and serve immediately.
If you've tried this recipe, come back and let us know how it was!