1. Place 4 slices of provolone on top of each pork chop (pile of cheese should be no more than 1/4 inch thick) and tear cheese to leave 1/8-inch border on all sides. Top each chop with 1 slice ham, and press down on ham to adhere to pork chop.
2. Adjust oven rack to middle position and heat oven to 425 degrees. Place Melba toast pieces, salt, garlic powder, onion powder, paprika, thyme, and sugar in heavy-duty zipper-lock freezer bag. Seal bag and pound with heavy blunt object (such as a rolling pin) until Melba toasts are crushed but still have some crumbs the size of small pebbles. Add 2 tablespoons mayonnaise to bag and work mayonnaise evenly into crumb mixture by gently squeezing outside of bag. Transfer Melba crumb mixture to large plate.
3. Using your fingers, coat 1 chop with 1 tablespoon mayonnaise. Transfer to plate with Melba crumbs, sprinkle top of pork chop with some Melba mixture, and press down firmly on chop to adhere crumbs. Flip chop and repeat, making sure that thick layer of crumbs coats both sides and edges. Transfer breaded pork chop to baking rack set over rimmed baking sheet. Repeat with remaining chops.
4. Bake pork chops until juices run clear and instant-read thermometer inserted into center of chop registers 145 to 150 degrees, 17 to 23 minutes. Remove chops from oven and let rest on rack for 5 to 10 minutes. Serve immediately.
**The Melba crumbs can be made weeks in advance and stored in the freezer. In this recipe, ham and cheese top the pork chops before they are breaded.