Start by seasoning the chicken breasts with salt, pepper, and garlic powder on both sides.
In a large skillet, heat the olive oil over medium-high heat. Add the chicken breasts and cook for about 6-7 minutes on each side, or until golden brown and cooked through. Remove the chicken from the skillet and set aside.
In the same skillet, reduce the heat to medium and add the heavy cream, basil pesto, and Parmesan cheese. Stir well to combine and let it simmer for about 3-4 minutes until the sauce thickens slightly.
Add the cherry tomatoes and spinach to the sauce, stirring until the spinach wilts and the tomatoes soften, about 2-3 minutes.
Return the cooked chicken to the skillet, spooning the creamy sauce over the top. Let it cook for an additional 2 minutes to heat through.
Serve the creamy pesto chicken garnished with fresh basil leaves.