Preheat oven to 180c/350f.
Using a meat mallet, flatten any thicker parts of the breasts to make them as even as possible, then sprinkle both sides with garlic powder (½ tsp) and salt and pepper (to taste).
Heat olive oil (1 tbsp) in a large frypan, and fry the chicken on medium-high heat for 2 minutes on each side, then place chicken in a baking dish. The chicken doesn't need to be cooked through at this stage because it will finish cooking in the oven.
Meanwhile, combine cream cheese spread (4 tbsp) and basil pesto (2 tbsp), mixing well to incorporate. Spread cream cheese mixture evenly over the top of the chicken.
Sprinkle shredded mozzarella (⅓ cup) evenly on top of cream cheese mixture, then bake for 20 mins or until cooked through (see notes).