Cook the penne pasta according to package instructions, then drain and set aside.
Heat olive oil in a large pan over medium heat and cook the steak bites until browned, about 4-5 minutes.
Remove the steak bites from the pan and set them aside.
In the same pan, melt butter over medium heat and sauté the garlic until fragrant, about 1 minute.
Add heavy cream to the pan and bring to a simmer.
Stir in Parmesan cheese, Cajun seasoning, garlic powder, salt, pepper, and red pepper flakes, and cook for 3-4 minutes until the sauce thickens.
Add the cooked pasta to the sauce and toss to coat.
Add the steak bites back to the pan and stir everything together.
Garnish with fresh parsley and serve immediately.