Using a sharp knife, carefully slice each chicken breast in half horizontally to create thin cutlets.
Season chicken with Italian seasoning, salt, and black pepper. Sprinkle flour over both sides and rub to coat evenly.
Heat olive oil and 1 tablespoon butter in a large skillet over medium heat.
Add chicken and cook for about 4 minutes per side until golden brown and cooked through. Remove chicken to a plate and cover to keep warm.
Add remaining butter to the same skillet, then add smashed garlic cloves. Reduce heat to medium-low and sauté for about 3 minutes until fragrant and lightly golden.
Pour in chicken broth and heavy cream, then add garlic powder. Stir and scrape up any browned bits from the pan.
Simmer sauce for 8–10 minutes until reduced and thickened by about half. Season with additional salt and pepper if needed.
Return chicken to the skillet and spoon sauce over the top. Cook for 2–3 minutes until heated through.
Garnish with fresh parsley if desired and serve warm.