Preheat oven to 400°F.

Lightly grease a 2-quart baking dish with cooking spray.

In a mixing bowl combine the basil pesto, mayonnaise, half of the Parmesan cheese, salt, and pepper; stir until well combined. Add shredded chicken and stir to combine. Spread evenly in prepared baking dish.

Arrange cherry tomatoes and mozzarella cheese over the chicken.

Sprinkle remaining Parmesan cheese on top.

Bake for 20 to 22 minutes, or until golden brown on top.