Bring a large pot of salted water to a boil and cook the penne according to package instructions until al dente; drain and set aside.
Meanwhile, heat 2 tsp olive oil in a large skillet over medium heat.
Season both sides of the chicken breasts with salt and pepper and cook in the skillet 3–4 minutes per side, or until cooked through; remove to a plate.
Spread 1 tsp prepared basil pesto on top of each cooked chicken breast and loosely cover with foil to keep warm.
In the same skillet over medium heat, add the butter and garlic and cook briefly, scraping up any browned bits from the pan.
Add the cubed cream cheese and whisk until mostly melted and incorporated into the butter.
Reduce heat to medium-low and gradually whisk in the heavy cream until smooth.
Stir in the grated Parmesan, 1/4 tsp salt, 1/4 tsp pepper, and the drained julienned sun-dried tomatoes; whisk until the sauce is smooth and cheese is melted.
Add the drained penne directly to the skillet and toss to coat evenly with the Alfredo sauce.
Serve the sauced penne with the pesto-topped chicken breasts alongside and enjoy immediately.