Cook rigatoni pasta in a large pot of salted boiling water until al dente. Reserve 1/2 cup of starchy pasta cooking water before draining.

Pat chicken cutlets dry with paper towels; season both sides generously with kosher salt, black pepper, and Italian seasoning. Heat olive oil and 1 tablespoon butter in a large deep skillet over medium-high heat.

Sear chicken cutlets for 4 to 5 minutes per side until golden brown and cooked to an internal temperature of 165°F (74°C). Transfer chicken to a cutting board to rest, then slice into thick strips.

Reduce heat to medium. Add remaining butter to the same skillet along with minced garlic, sun-dried tomatoes, and red pepper flakes. Sauté for 1 to 2 minutes until garlic is fragrant and tomatoes release flavor.

Pour in chicken broth to deglaze the skillet, using a wooden spoon to scrape up all golden browned bits from the pan. Simmer for 2 minutes to reduce slightly, then pour in heavy cream. Bring to a gentle simmer for 3 minutes until thickened.

Turn heat to low. Whisk in grated Parmesan cheese until melted and velvety. Stir in fresh baby spinach and cook for 1 minute until wilted.

Add drained rigatoni directly into the sauce, tossing vigorously until every pasta tube is coated in silky cream (splash in reserved pasta water if needed to loosen). Arrange sliced chicken over top, garnish with fresh basil, cracked pepper, and serve warm!