01 - Preheat oven to 400°F. Lightly grease a 9x13-inch baking dish.
02 - Pat chicken breasts dry. Drizzle both sides with olive oil and season with salt and pepper. Arrange in the baking dish in a single layer.
03 - In a medium bowl, combine spinach, artichoke hearts, cream cheese, sour cream, Parmesan, garlic, and crushed red pepper flakes. Mix until well blended.
04 - Spread the spinach-artichoke mixture evenly over each chicken breast.
05 - Spoon basil pesto over the creamy topping, spreading gently.
06 - Sprinkle shredded mozzarella evenly over the top.
07 - Bake uncovered for 30-35 minutes, or until the chicken is cooked through (internal temperature reaches 165°F) and the cheese is golden and bubbling.
08 - Allow to rest for 5 minutes before serving. Garnish with fresh basil if desired.