Prepare the Chicken: Start by preheating your oven to 400°F (200°C). Take the chicken breasts and season them with salt and pepper. Dredge each breast in flour, dip in the beaten egg, and then coat with breadcrumbs, pressing them into the chicken for an even crust.
Cook the Chicken: Heat olive oil in a large oven-safe skillet over medium heat. Once hot, add the breaded chicken breasts and cook for about 5-7 minutes per side until golden brown. Remove from heat and set aside.
Cook the Pasta: In a large pot, bring salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Drain and set aside, reserving about ½ cup of the pasta water.
Combine Sauce and Pasta: In the same pot, stir the marinara sauce with the reserved pasta water over low heat. Add the cooked penne and stir well to combine.
Layer the Ingredients: Slice the cooked chicken breasts and place them on top of the pasta mixture in the pot. Sprinkle mozzarella and grated Parmesan over the chicken slices.
Bake: Transfer the skillet to the preheated oven and bake for 15-20 minutes, or until the cheeses are bubbly and golden.
Garnish and Serve: Remove from the oven and let it cool for a few minutes. Garnish with fresh basil leaves before serving.