In a large bowl, combine the buttermilk, garlic powder, onion powder, paprika, salt, and black pepper. Add the chicken breasts, ensuring they are fully submerged. Cover and refrigerate for at least 1 hour or up to overnight for best flavor and tenderness.
Preheat your oven to 400°F. Line a baking sheet with parchment paper.
In a shallow dish, mix the flour, panko breadcrumbs, and grated Parmesan cheese. Remove the chicken from the buttermilk, allowing excess to drip off, then dredge each piece in the breadcrumb mixture, pressing gently to adhere.
Place the coated chicken on the prepared baking sheet. Bake for 25-30 minutes, or until the chicken is golden brown and reaches an internal temperature of 165°F. For extra crispiness, broil for an additional 2-3 minutes.
While the chicken is baking, prepare the sandwich rolls by toasting them lightly if desired.
Once the chicken is done, let it rest for a few minutes. Slice the chicken into strips.
To assemble the sandwiches, spread a generous amount of Caesar dressing on the bottom half of each roll. Layer with chopped romaine lettuce, followed by the crispy chicken strips. Top with additional Parmesan cheese and the top half of the roll.
Serve immediately with lemon wedges on the side for an extra burst of flavor.