Preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish.
Season the chicken with salt, black pepper, garlic powder, and Italian seasoning.
Heat olive oil in a large skillet over medium heat. Sear the chicken for 2–3 minutes per side until lightly golden.
Transfer the chicken to the prepared baking dish.
Scatter the halved cherry tomatoes and minced garlic around the chicken.
Top each chicken breast with shredded mozzarella or fresh mozzarella slices.
Bake the Caprese Chicken Casserole uncovered for 25–30 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the cheese is fully melted and bubbly.
Remove from the oven and garnish with fresh basil leaves.
Drizzle with balsamic glaze and sprinkle with red pepper flakes if desired.
Serve immediately with pasta, rice, mashed potatoes, roasted vegetables, or a crisp green salad.