Pat chicken cutlets completely dry with paper towels. Season both sides evenly with Italian seasoning, garlic powder, kosher salt, and freshly cracked black pepper.

Heat olive oil and butter in a 12-inch heavy cast-iron or stainless skillet over medium-high heat. Sear the cutlets undisturbed for 4 minutes per side until deeply golden browned and almost cooked through (165°F / 74°C). Transfer cutlets to a clean plate and set aside.

Reduce skillet heat to medium. Add sliced sun-dried tomatoes and minced garlic to the residual pan drippings. Sauté for 60 seconds until fragrant, stirring constantly with a wooden spoon so garlic does not scorch.

Pour in the chicken broth, scraping up all caramelized golden fond from the skillet bottom. Bring to a gentle simmer for 2 minutes to reduce slightly, then pour in heavy cream and stir until unified.

Reduce heat to low. Whisk in freshly grated Parmigiano-Reggiano cheese in small batches until silky and melted. Stir in the fresh baby spinach and let it wilt into the warm cream for 1 to 2 minutes.

Nestle the seared chicken cutlets and any accumulated resting plate juices back into the skillet. Spoon glossy sauce over the chicken, garnish with fresh basil ribbons and extra cracked pepper, and serve immediately!