Heat the olive oil in a large pot over medium heat. Add the diced onion and cook for about 5 minutes until softened and translucent. Add the minced garlic and continue cooking for another 3-4 minutes until fragrant but not browned. Stir in the crushed tomatoes and add the fresh basil sprigs. Reduce heat to low and simmer gently for 30 minutes, stirring occasionally. The sauce will deepen in color and flavor as it reduces slightly. Season with kosher salt and black pepper to taste, then remove and discard the basil sprigs. I like to let the sauce simmer longer than 30 minutes if I have time—the flavors really mellow and marry together beautifully.
Set up three shallow bowls for your breading station. In the first bowl, combine the all-purpose flour with a pinch of kosher salt and black pepper. In the second bowl, beat the room-temperature eggs thoroughly until well combined and slightly frothy. In the third bowl, mix together the panko bread crumbs, garlic powder, and 1 cup of finely grated Parmesan. In a separate small bowl, combine the shredded mozzarella with the remaining 1 cup of finely grated Parmesan—this is your topping mixture. Having everything prepped and organized before you start cooking the chicken will make the process smooth and efficient.
Place the boneless, skinless chicken cutlets on a cutting board. If they're thicker than 1/4 inch, gently pound them between two pieces of plastic wrap or parchment paper until they reach an even 1/4-inch thickness—this ensures they cook evenly and quickly. Season both sides of each cutlet generously with kosher salt and black pepper. Set the pounded chicken aside on a clean plate while you heat your oil.
Heat the vegetable oil in a large heavy-bottomed pot or Dutch oven to 350°F (use a thermometer to be precise). While the oil heats, begin breading the chicken: take one seasoned cutlet, dredge it thoroughly in the flour mixture, shake off excess, dip it in the beaten egg, then coat completely with the panko-Parmesan mixture from Step 2, pressing gently so the breadcrumbs adhere. Once the oil reaches temperature, carefully add 2-3 breaded cutlets at a time, avoiding crowding. Fry for about 1 minute per side until golden brown and crispy. Transfer the fried chicken to a paper towel-lined wire rack to drain excess oil. Repeat with remaining cutlets. I find that working in batches actually gives me better results—the oil temperature stays more consistent and the chicken crisps up beautifully without steaming.
Preheat your broiler to high. Arrange the fried chicken cutlets on a baking sheet or large oven-safe skillet, spacing them evenly. Top each cutlet with about 2-3 tablespoons of the warm marinara sauce from Step 1, spreading it gently over the chicken. Sprinkle the mozzarella-Parmesan mixture from Step 2 generously over each cutlet. Carefully slide the pan under the preheated broiler and broil for 2-3 minutes, watching carefully, until the cheese melts completely, bubbles, and develops light golden-brown spots. Watch carefully—broilers vary in intensity and you want the cheese melted and slightly browned, not burnt.
Remove the chicken Parmesan from the broiler and let it rest for 1-2 minutes before serving. Transfer to serving plates and drizzle each portion with a bit more of the warm marinara sauce from Step 1 if desired. Top with fresh chopped basil just before serving so it stays bright and aromatic. The combination of the crispy, golden-brown breading, melted cheese, and bright sauce creates the perfect balance of textures and flavors.