Bring a large pot of salted water to a boil. Add the cheese tortellini and cook until just tender, typically about 3-4 minutes. Drain and set aside, leaving some steam to help keep them warm.

In a medium saucepan over medium heat, melt 3 tablespoons of butter. Add the minced garlic and cook for about 1 minute until fragrant. Stir in 2 cups of heavy cream, allowing it to simmer gently, and mix in the parmesan cheese until melted and smooth.

In a large mixing bowl, gently fold the cooked tortellini into the creamy Alfredo sauce until each piece is well-coated.

Pour the tortellini mixture into a greased baking dish, spreading it evenly. Top generously with 1 cup of shredded mozzarella.

Preheat your oven to 350°F. Bake the dish for about 25-30 minutes or until the top is bubbly and golden brown.