Preheat the air fryer to 375°F (190°C) for 5 minutes.
Pat the chicken breasts dry with paper towels.
Brush both sides of the chicken breasts with 1 tablespoon olive oil.
Season the chicken breasts evenly with salt, black pepper, and garlic powder.
Place the chicken breasts in the air fryer basket in a single layer.
Cook the chicken breasts in the air fryer for 9 minutes.
Flip the chicken breasts over and continue cooking for another 9 minutes, or until the internal temperature reaches 165°F (74°C).
While the chicken cooks, prepare the pesto: In a food processor, combine the fresh basil leaves, grated Parmesan cheese, pine nuts, and garlic clove.
Pulse a few times to chop the ingredients.
With the processor running, slowly drizzle in 3 tablespoons extra virgin olive oil until the mixture is smooth and well combined.
Add lemon juice and pulse once to mix.
Remove the pesto from the processor and set aside.
Once the chicken breasts are cooked, remove them from the air fryer and let them rest for 3 minutes.
Slice the chicken breasts if desired, then spoon the prepared pesto generously over the top.
Serve immediately.