Slice the chicken breasts horizontally to create 4-6 thin cutlets. Whisk together the egg and a splash of milk with garlic powder, salt, and pepper in one bowl. In another bowl, combine breadcrumbs. Dredge cutlets in egg mixture, then coat in breadcrumbs and fry in vegetable oil for about 5 minutes on each side until golden brown. Drain on paper towels.

Preheat the oven to 450°F (232°C). Mix softened butter with minced garlic, chopped parsley, and Parmesan. Slice the hoagies or baguette lengthwise and spread garlic butter generously on each side. Toast in the oven for 3-4 minutes until golden and crispy.

In a bowl, whisk together mayonnaise, sour cream, lemon juice, Dijon mustard, anchovy paste, Worcestershire sauce, and grated garlic until smooth. Taste and adjust seasoning to ensure it's bold and zesty.

Toss the chopped romaine lettuce with Caesar dressing, ensuring even coating. Layer crispy chicken cutlets on one side of toasted bread, then add dressed romaine. Sprinkle additional Parmesan on top before closing the sandwich.

Slice the sandwiches in half and serve immediately for the best texture and flavors.