Assemble the dry rub by mixing the brown sugar, smoked paprika, garlic powder, mustard powder, salt, and pepper together in a bowl.

Using a sharp knife, make a series of crisscross cuts in a diamond pattern about 1/2 inch deep across the entire ham.

Coat the ham in the dry rub, working it into the cut areas so the flavors sink in. You can do this a day or two before cooking.

Grill the ham using indirect heat for 2 to 2-1/2 hours. The ham is done when its internal temperature reaches 140°F (60℃).

While the ham cooks, make the glaze by combining bourbon, maple syrup, and butter in a small saucepan over high heat.

Stir the glaze until it comes to a boil. Lower the heat and let it reduce for 10 minutes, until it thickens.

Brush the glaze onto the ham, turning it to coat each side. Let the glaze set for 10 to 15 minutes between each coat. Glaze at least three times, cooking a few more minutes after the last layer.

Let the ham rest for 5 to 10 minutes under a foil tent before slicing.