Adjust an oven rack to the lower third position and preheat the oven to 325°F. In a small mixing bowl, whisk together the honey, butter, mustard, onion powder, paprika, black pepper, cinnamon, ginger, cloves, and nutmeg until smooth and fully combined.

Place the ham, fat-cap side up, on a wire rack set inside a large roasting pan. Using a pastry brush, generously coat the ham—working the glaze between the slices—with half of the prepared glaze. Pour enough water into the bottom of the roasting pan to reach approximately ¼ inch. Tightly cover the entire pan with aluminum foil

Transfer the ham to the oven and bake, adding additional water as needed to prevent the pan from drying out, until an instant-read thermometer inserted into the thickest portion of the ham registers 130°F (54°C), about 2 hours.

Carefully remove the roasting pan from the oven. Uncover the ham and increase the oven temperature to 400°F (204°C). Brush the ham with half of the remaining glaze.

Return the ham to the oven and continue baking until the glaze becomes caramelized and slightly tacky, about 10 minutes. Remove the ham once more, brush with the remaining glaze, and evenly sprinkle granulated sugar over the surface, gently pressing it onto the ham. Return to the oven and bake until the internal temperature reaches 145°F (63°C) and the sugar forms a crisp, caramelized shell, about 10 minutes longer. Allow the ham to rest briefly before transferring to a serving platter