Bring a large pot of salted water to a boil. Add bowtie pasta and cook until al dente according to package directions, about 10-12 minutes. Reserve 1/2 cup of pasta water, then drain and set aside.

In a large skillet, melt 1 tablespoon of butter over medium-high heat. Add ground beef and season with 1 tablespoon of Cajun seasoning, salt, pepper, and optional red pepper flakes. Cook for 8-10 minutes until browned and slightly crispy.

Remove the cooked beef from the skillet using a slotted spoon and set aside. Leave about 1 tablespoon of fat in the pan, drain excess.

Reduce heat to medium. Add remaining butter and minced garlic to the same skillet. Sauté for 30 seconds until fragrant but not browned.

Add the softened cream cheese and stir continuously as it melts into the butter and garlic, breaking it up to incorporate smoothly.

Slowly whisk in the milk or half-and-half, stirring constantly to create a smooth, creamy base without lumps.

Mix in the grated Parmesan and the remaining 1 tablespoon of Cajun seasoning. Simmer for 2-3 minutes until the sauce has thickened slightly. Adjust seasoning as needed.

Return the cooked ground beef to the skillet, then add the cooked pasta. Toss everything together using tongs or large spoons until well coated.

If the sauce feels too thick, stir in reserved pasta water starting with 2 tablespoons until it reaches your desired consistency.

Serve hot and garnish with extra Parmesan, chopped parsley, or a sprinkle of red pepper flakes if desired.