Preheat your oven to 400°F (200°C) and lightly grease a 9×13-inch baking dish.

In a large pot of boiling salted water, cook the pasta for 2 minutes less than the package directs. Drain and set aside.

In a skillet over medium-high heat, warm the olive oil and season the diced chicken with salt and pepper. Sauté until golden brown and cooked through, approximately 5–6 minutes. Remove them from the skillet.

Using the same skillet, melt the butter over medium heat, then add the garlic and sauté until fragrant, about 30 seconds.

Incorporate the heavy cream and whole milk, allowing it to simmer for 2–3 minutes until slightly thickened. Mix in the basil pesto and Parmesan until you have a smooth sauce.

Return the chicken and pasta to the skillet, tossing to coat evenly. Transfer to your prepared baking dish.

Sprinkle shredded mozzarella and the remaining Parmesan on top.

Bake uncovered for 20–25 minutes, until the cheese is golden and bubbling.

Allow the dish to rest for 5 minutes before serving.