Bring a large pot of salted water to a boil. Add bowtie pasta and cook until al dente according to package directions, usually 11-13 minutes. Reserve 1/2 cup pasta water, then drain and set aside.

In a large 12-inch skillet over medium heat, add ground beef. Break it up with a spatula and sprinkle Cajun seasoning over the beef. Cook until browned and fully cooked through (no longer pink), about 6-8 minutes. If using 85/15 ground beef, you can leave the small amount of fat in the pan. Transfer the cooked beef to a plate.

In the same skillet, melt butter over medium heat. Add minced garlic and cook 30 to 60 seconds until fragrant but not browned.

Pour in heavy cream and simmer gently 3 to 4 minutes, stirring occasionally, until slightly thickened.

Reduce heat to low. Stir in shredded cheddar and Parmesan until melted and smooth. Season with salt and black pepper to taste.

Return the beef to the skillet, add cooked pasta, and toss until everything is coated in the sauce. If sauce feels too thick, splash in 2-3 tablespoons of reserved pasta water, adding more if needed.

Remove from heat and sprinkle with chopped fresh parsley. Serve hot.