Heat oven to 250ºF.
Remove ham from bag, rinse, and drain thoroughly. Place ham, cut-side down, in a roasting pan. Using a small paring knife or clean utility knife set to the smallest blade setting, score the ham from bottom to top, spiraling clockwise as you cut. If you're using a paring knife, be careful to only cut through the skin and first few layers of fat. Rotate the ham after each cut so that the scores are no more than 2 inches across. Once you've made it all the way around, move the knife to the other hand and repeat, spiraling counter-clockwise. The aim is to create a diamond pattern all over the ham. Don't worry too much about precision here.
Tent the ham with heavy duty foil, insert a thermometer, and cook for 3 to 4 hours, or until the internal temperature at the deepest part of the meat registers 130ºF.
Remove and use tongs to pull away the diamonds of skin and any sheets of fat that come off with them.
Heat oven to 350ºF.
Dab the ham dry with paper towels, then, using either a basting brush or a clean paint brush ("clean," as in, "never touched paint"), brush on a liberal coat of mustard. Sprinkle on brown sugar, packing loosely as you go until the ham is coated. Spritz this layer lightly with bourbon, then loosely pack on as much of the crushed cookies as you can.
Insert the thermometer (don't use the old hole) and return to the oven, uncovered. Cook until interior temperature reaches 140ºF, approximately 1 hour.
Let the roast rest for 30 minutes before carving.