Bring a large pot of salted water to a boil and cook pasta until al dente, about 8-10 minutes. Reserve ½ to ⅓ cup of pasta water before draining.

Melt unsalted butter in a skillet over medium heat and sauté sliced cherry tomatoes for 5-7 minutes until softened.

Add minced garlic, red pepper flakes, and Italian seasoning to the skillet; cook for 30 seconds until fragrant.

Pour reserved pasta water into the skillet, then add mascarpone cheese and grated Parmesan, stirring until melted and creamy.

Toss drained pasta with the sauce, adding torn basil leaves, and adjust seasoning with salt and pepper.

Serve immediately, garnishing with additional basil and Parmesan cheese if desired.