Bring a large pot of salted water to a boil. Add penne and cook until al dente, following the time on the box. Drain and set aside, but keep 1 cup of the cooked pasta water.
Heat olive oil in a large skillet over medium high heat. Add onion and cook until softened and translucent, about 3-4 minutes. Add garlic and cook 30 seconds to lightly brown it.
Add tomato sauce, tomato paste, whipping cream, Parmesan cheese, oregano, sugar and salt and pepper, bringing to a low boil and cook for 5 minutes as it thickens.
Add cooked penne pasta and reserved pasta water into the skillet, stirring to combine.
Add cherry tomatoes, shredded mozzarella cheese and basil to the skillet, stirring until everything is fully warmed up.
Serve or bake: You can serve as is, or you can bake it. It’s really up to you if you have the extra time. To bake, pour mixture into a 11x13 baking dish, sprinkle 1/4 cup extra shredded mozzarella cheese on top and bake at 400 degrees F for 20 minutes.