Heat the olive oil in a large skillet or Dutch oven over medium heat. Add the chopped onion and cook until softened, about 5 minutes. Stir in the minced garlic and red pepper flakes and cook for another minute until fragrant.

Pour in the crushed tomatoes, vegetable broth, and Italian seasoning. Bring the mixture to a simmer and cook for 5-7 minutes, allowing the flavors to meld together.

Add the uncooked gnocchi directly to the simmering sauce. Stir gently to coat, cover the skillet, and cook for 3-5 minutes, or until the gnocchi are tender and float to the surface.

Reduce the heat to low and stir in the heavy cream and grated Parmesan cheese. Continue stirring until the cheese is melted and the sauce is smooth and creamy.

Remove the skillet from the heat. Stir in the fresh basil and season with salt and pepper to taste. Serve immediately, garnished with extra Parmesan cheese and fresh basil leaves.