Preheat the oven to 400ºF. In a bowl, combine the brown sugar, cayenne, garlic powder, paprika, salt, pepper, and olive oil.

Place the pork loin on a parchment lined baking sheet or in a large casserole dish with the fat cap facing up. Begin packing the brown sugar and spice mixture all over the surface of the pork loin (no need to get the bottom). The moisture from the pork loin should help the sugar mixture stick to the surface.

Transfer the pork loin to the oven. Roast at 400ºF for ten minutes, then reduce the heat to 350ºF and continue to roast for about 15 minutes per pound of roast, or until the internal temperature reaches 145ºF. Always use a meat thermometer just to be sure.

After roasting, let the pork loin rest for 10 minutes before slicing into ½-inch thick slices and serving.