Begin by slicing the chicken breasts into thin cutlets for even cooking. In a bowl, whisk together the egg and milk, then add garlic powder, salt, and pepper for seasoning.

In another bowl, place the breadcrumbs. Dip each chicken cutlet into the egg mixture, ensuring it's well-coated, then dredge it in the breadcrumbs.

In a large skillet, heat the vegetable oil over medium-high heat until it reaches 350°F. Carefully add the breaded chicken cutlets, frying them for about 5 minutes on each side until they turn golden brown.

While the chicken is frying, prepare the garlic butter by mixing softened butter with minced garlic. Split open the hoagies or baguette, and spread the garlic butter inside.

Toast them in a preheated oven at 450°F or under the broiler for 3-4 minutes until golden and aromatic.

In a bowl, combine mayonnaise, sour cream (or Greek yogurt), lemon juice, Dijon mustard, anchovy paste, Worcestershire sauce, and finely grated Parmesan. Whisk until smooth.

Layer each toasted bread piece with a crispy chicken cutlet, toss the chopped romaine with the Caesar dressing and add it atop the chicken. Sprinkle extra Parmesan before closing.

Cut each sandwich in half for easy handling and serve them warm.