01 - Preheat oven to 400°F. Lightly grease a 9x13-inch baking dish with cooking spray or a small amount of olive oil.
02 - Pat chicken breasts dry with paper towels. Drizzle both sides with olive oil and season evenly with salt and black pepper. Arrange chicken in a single layer in the prepared baking dish.
03 - In a medium bowl, combine thawed spinach, chopped artichoke hearts, softened cream cheese, sour cream, Parmesan cheese, minced garlic, and red pepper flakes. Mix thoroughly until all ingredients are well blended and smooth.
04 - Spread the spinach-artichoke mixture evenly over the top of each chicken breast, covering the surface completely.
05 - Spoon basil pesto over the creamy spinach-artichoke topping on each chicken breast. Spread gently to create an even layer without pushing the creamy mixture off the chicken.
06 - Evenly sprinkle shredded mozzarella cheese over the pesto layer on all chicken breasts.
07 - Bake uncovered for 30 to 35 minutes until chicken is cooked through (internal temperature reaches 165°F) and the cheese is golden brown and bubbling.
08 - Remove from oven and let chicken rest for 5 minutes to allow juices to redistribute. Garnish with fresh basil leaves if desired before serving.