Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Reserve 1/2 cup of pasta water, then drain the pasta and set aside.
Stir in the heavy cream and bring it to a gentle simmer. Reduce the heat to low and add the pesto, stirring until fully combined with the cream.
Add the cooked pasta to the skillet, tossing it in the creamy pesto sauce. If the sauce is too thick, add a splash of reserved pasta water to reach your desired consistency.
Stir in the grated Parmesan cheese and season with salt and black pepper to taste. Continue tossing until the cheese melts and the pasta is evenly coated.
Remove from heat and transfer to serving plates. Garnish with halved cherry tomatoes or a sprinkle of pine nuts if desired. Serve warm and enjoy your creamy pesto pasta!