Combine the ground beef, breadcrumbs, egg, garlic powder, onion powder, salt, and black pepper in a large bowl. Mix until just blended, then fold in 1/2 cup of the shredded Pepper Jack cheese.
Divide the mixture into four equal portions and shape each into a small oval patty about 1 inch thick.
Heat the olive oil in a large skillet over medium heat. Add the patties and cook for 5 to 6 minutes per side until browned and cooked through.
Sprinkle the remaining 1/2 cup shredded Pepper Jack cheese over the patties in the last minute of cooking so it melts.
While the patties finish, stir the black beans and corn together in a microwave-safe bowl and heat for 1 to 2 minutes until warm.
Divide the bean and corn mixture among four bowls. Place one cheesy meatloaf patty in each bowl and top with avocado slices.