In a large skillet or sauté pan, heat the olive oil over medium heat. Add the sliced garlic and cook for 1-2 minutes until fragrant and lightly golden. Be careful not to burn it.

Pour in the crushed tomatoes, salt, and pepper. Stir well, bring to a simmer, then reduce the heat to low. Let the sauce simmer gently for at least 15-20 minutes for the flavors to meld. The sauce should thicken slightly.

While the sauce simmers, preheat your oven to 400°F (200°C). Bring a large pot of heavily salted water to a rolling boil. Add the penne and cook according to package directions, but remove it 2 minutes early so it is very al dente. It will finish cooking in the oven.

Before draining the pasta, reserve about 1 cup of the starchy pasta water. Drain the pasta well.

Turn off the heat for the sauce. Add the drained pasta directly to the skillet with the sauce. Add the cubed mozzarella, 1/2 cup of grated Parmigiano-Reggiano, and the torn basil leaves. Stir everything together until well combined. If the sauce seems too thick, add a splash of the reserved pasta water to loosen it.

Transfer the pasta mixture to a 9x13 inch baking dish (or a similar-sized oven-safe dish) and spread it into an even layer. Sprinkle the remaining 2 tablespoons of Parmigiano-Reggiano on top.

Bake for 15-20 minutes, or until the sauce is bubbly and the cheese is completely melted and slightly golden on top. For a crispier, more browned top, you can switch to the broiler for the last 1-2 minutes, watching it carefully to prevent burning.

Remove from the oven and let it rest for 5-10 minutes before serving. This allows the dish to set slightly. Garnish with additional fresh basil leaves and serve hot.