Bring a large pot of salted water to a boil.
Cook the ravioli according to the package instructions.
Drain and set aside.
In a large pan, heat the olive oil over medium heat.
Add the chopped onion and minced garlic.
Sauté until fragrant and soft, about 3-4 minutes.
Add the cream to the pan, stirring constantly.
Mix in the Parmesan and Mozzarella cheeses, allowing them to melt completely into the sauce.
Add milk, salt, and pepper to the mixture.
Continue cooking for a few minutes until the sauce becomes creamy and smooth.
Add the cooked ravioli to the pan and toss gently to coat them evenly with the sauce.
Top with crumbled bacon and serve immediately.