Bring a large pot of salted water to a boil and cook the penne according to package directions until al dente. Drain and set aside.
While the pasta cooks, heat the olive oil in a large skillet over medium heat. Add the diced onion and cook for 3 minutes until it softens.
Add the ground turkey to the skillet. Break it up with a spoon and cook until it is no longer pink, about 5 to 6 minutes.
Stir in the minced garlic and cook for 30 seconds until fragrant.
Pour in the tomato sauce, salt, and black pepper. Let the mixture simmer for 4 minutes.
Reduce the heat to low and slowly stir in the heavy cream until the sauce turns a light orange color and looks smooth.
Add the drained pasta to the skillet and toss until every piece is coated with sauce.
Remove the skillet from the heat and stir in the chopped basil. Serve right away with grated parmesan on top.