Preheat oven to 375°F (190°C).
In a small skillet, heat 1 tbsp Extra Virgin Olive Oil over medium heat. Add minced garlic and chopped spinach; sauté for 1–2 minutes until wilted. Remove from heat.
Slice a 3-inch pocket horizontally into each chicken breast without cutting all the way through.
Season chicken interior and exterior with garlic powder, dried thyme, sea salt, and black pepper.
Stuff each pocket with sautéed garlic spinach, slices of Brie cheese, and cranberries. Secure seams with wooden toothpicks.
Heat remaining 1 tbsp Extra Virgin Olive Oil in an oven-safe skillet over medium-high heat. Sear chicken for 2–3 minutes per side until golden brown.
Transfer to oven (or ceramic baking dish) and bake at 375°F (190°C) for 18–22 minutes until internal temperature reaches 165°F (74°C) on a digital meat thermometer.
In a small saucepan, simmer honey, balsamic vinegar, and Dijon mustard for 2 minutes.
Brush glaze over hot baked chicken, garnish with fresh rosemary and thyme, remove toothpicks, and rest 5 minutes before serving.