Preheat your oven to 375°F (190°C).

Slice each chicken breast in half horizontally to create thinner cutlets. Place the cutlets between two sheets of plastic wrap and gently pound them to an even thickness of about 1/4 inch.

In a mixing bowl, combine the chopped spinach, ricotta cheese, mozzarella cheese, Parmesan cheese, garlic powder, Italian seasoning, salt, and pepper. Mix until well combined.

Lay the chicken cutlets flat on a clean surface. Spoon about 2 tablespoons of the cheese and spinach mixture onto one end of each cutlet. Roll the chicken tightly around the filling, securing it with toothpicks if necessary.

In a large oven-safe skillet, heat the olive oil over medium heat. Add the chicken rollatini and sear for about 3-4 minutes on each side until golden brown.

Pour the marinara sauce over the chicken in the skillet. Transfer the skillet to the preheated oven and bake for 20-25 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).

Remove from the oven and let rest for 5 minutes before serving. Garnish with fresh basil leaves if desired.