Preheat the oven to 450 degrees F (230 degrees C). Lightly spritz bottom and sides of a medium baking pan with olive oil spray.

Using a sharp knife, carefully slice into the side of each chicken breast to form a pocket but do not slice all the way through. Season the insides and outsides with salt and pepper.

In a small bowl, combine diced avocado and the bacon. Divide the mixture in half and stuff each chicken breast. Use toothpicks to secure the pockets and place into baking pan.

Mix together panko, mozzarella cheese, and olive oil in a small bowl. Brush 1 tablespoon pesto on top of each breast. Cover each breast with the panko mixture, pressing into the pesto so mixture adheres.

Roast in the preheated oven until chicken is no longer pink in the center and the juices run clear, 20 to 25 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).