Place each chicken breast on a cutting board and slice them in half horizontally to create a pocket, being careful not to cut all the way through.
In a mixing bowl, combine the diced mozzarella, halved cherry tomatoes, chopped basil, and balsamic glaze. Stir until well mixed.
Stuff each chicken breast pocket with the Caprese mixture, ensuring an equal amount in each.
In a small bowl, mix together the olive oil, garlic powder, Italian seasoning, salt, and pepper.
Brush the outside of each stuffed chicken breast with the oil mixture, coating evenly.
Place the stuffed chicken breasts in a greased baking dish.
Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 15 minutes or until the chicken is cooked through and the internal temperature reaches 165°F (75°C).
Let the chicken rest for a few minutes before slicing, and serve warm.
Notes
Let the chicken rest before slicing for better juiciness.