Preheat the oven to 400°F (200°C). Pound the chicken breasts to an even thickness using a meat mallet.

In a shallow dish, combine flour, salt, black pepper, garlic powder, and onion powder.

Pour the buttermilk into another shallow dish.

In a third dish, mix panko breadcrumbs with grated Parmesan cheese.

Dredge each chicken breast in the flour mixture and shake off the excess.

Dip it into the buttermilk and then coat thoroughly in the breadcrumb mixture.

Heat olive oil in a large skillet over medium heat. Fry each chicken breast until golden and crispy, about 4 minutes per side.

Remove and place them on a baking sheet. Bake in the preheated oven for about 15 minutes or until fully cooked through.

Mix melted butter and minced garlic in a small bowl. Brush the cut sides of the sandwich rolls with this mixture and place on a baking sheet.

Toast the rolls in the oven for about 5 minutes or until golden brown.

Assemble the sandwiches: place each piece of chicken on the bottom half of the toasted roll, top with shredded Romaine lettuce, drizzle with Caesar dressing, and sprinkle with shaved Parmesan cheese. Close with the top half of the roll.