Preheat your oven to 400ºF.
Heat 2 tablespoons of olive oil in a large heavy-duty (oven-safe) skillet over medium-high heat.
Add the onion to the skillet and cook for 2 to 3 minutes or until softened and golden.
Add the garlic and sauté for 30 seconds until fragrant.
Pour in the crushed tomatoes and add the Italian seasoning, garlic powder, crushed red pepper, salt, and pepper. Sauté for 2 minutes.
Add the chicken breasts to the skillet, cooking for 1 to 2 minutes per side until browned.
Transfer the pan to the oven and bake for 10 minutes.
Flip the chicken breasts and top with mozzarella. Bake for another 10 minutes.
Remove from oven, garnish with basil, and serve immediately.