Bring a medium pot of salted water to a boil. Add the rigatoni and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, melt 2 tablespoons of the unsalted butter over medium-high heat. Add the minced garlic and sauté for about 1 minute until fragrant.
Add the steak tips to the skillet, season with salt and black pepper, and cook for about 5-7 minutes, stirring occasionally, until browned and cooked to your desired doneness. Remove the steak from the skillet and set aside.
In the same skillet, melt the remaining 2 tablespoons of butter. Add the heavy cream, garlic powder, and a pinch of salt. Stir well and let the sauce simmer for about 2-3 minutes.
Add the cooked rigatoni pasta to the skillet and stir to combine. Gradually add the shredded mozzarella and Parmesan cheese, stirring continuously until the cheese melts and creates a creamy sauce.
Return the steak tips to the skillet and gently toss everything together until well combined. Remove from heat.
Serve hot, garnished with chopped parsley for a touch of freshness.