Cook the gnocchi according to package instructions and set aside.
In a large skillet, heat olive oil over medium heat and sauté the diced onion until translucent.
Add the minced garlic to the skillet and cook for another minute until fragrant. Then, add the sausage, breaking it apart as it browns.
Once the sausage is browned, stir in the crushed tomatoes and bring the mixture to a simmer.
Pour in the heavy cream and stir to combine, then let it simmer for a few minutes to thicken slightly.
Add grated Parmesan cheese, stirring until melted and smooth. Season with salt and pepper to taste.
Gently fold in the cooked gnocchi, ensuring they are well-coated in the sauce and heated through.
Serve warm, garnished with fresh basil if desired.