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. 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.
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.
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 1/8 of the cheese on each tortilla and top with 1/8 of the pork, onions, corn and jalapenos. Top with another tortilla and another 1/8 of the cheese, pork, onions, corn and jalapenos. Top with another tortills 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.