Preheat a grill or grill pan. Season the pork loin with salt and pepper. In a small bowl combine the brown sugar, chili powder, garlic, oregano, onion powder, lime juice and canola oil and mix to form a paste. Rub the paste all over the pork. Cover and refrigerate for 2 hours. Place the onion and the corn on the grill and grill until tender and slightly charred. Remove and set aside. With a knife, remove the kernels from the corn. Remove the pork from the refrigerator and place on the grill. Grill to medium, about 4 minutes per side. Remove from the grill and slice into thin slices. Wrap the tortillas in a damp paper towel or clean cloth and place in the microwave for 20 seconds to soften. Place 4 corn tortillas on a flat surface. Place 1/8th of the cheese on each tortilla and top with 1/8th of the pork, onions, corn, and jalapenos. Top with another tortilla and another 1/8th of the cheese, pork, onions, corn, and jalapenos. Top with another tortillas and press down firmly with your hands on each stack. Brush the tops of each stack with some of the canola oil and place on a baking sheet. Place in the oven and cook for 10 minutes, or until the cheese melts and the tortillas are golden brown. Remove from the oven and garnish with sour cream, salsa, guacamole, and cilantro.