Have all your ingredients measured and ready before you start, since this recipe moves quickly once you begin cooking.

Heat olive oil in your large deep skillet or Dutch oven over medium-high heat until shimmering, about 1-2 minutes. Add the ground beef and use a wooden spoon to break it up into small crumbles as it cooks. Cook for 6-8 minutes, stirring occasionally, until the beef is nicely browned with no pink remaining. If using higher-fat beef and the pan looks very greasy, carefully tilt the pan and spoon out excess grease into a heat-safe container, leaving about 1-2 tablespoons behind for flavor.

Add butter directly to the pan with the cooked beef. Let it melt completely, swirling the pan to coat everything. Once the butter is melted and sizzling, add minced garlic, Italian seasoning, red pepper flakes, smoked paprika, salt (about 1/2 teaspoon to start), and black pepper (1/4 teaspoon). Stir everything together and cook for 1-2 minutes until fragrant. Watch the garlic carefully so it becomes fragrant and lightly golden, but not brown or burned.

Pour in all 4 cups of beef broth, scraping the bottom of the pan with your spoon to release any flavorful brown bits. Add your uncooked pasta right to the pan. Give everything a good stir to make sure the pasta is submerged in the liquid. Increase the heat to high and bring everything to a rolling boil. Once boiling, immediately reduce heat to medium-low and cover with your lid. Let it simmer gently for 12-15 minutes, stirring every 3-4 minutes to prevent sticking. You'll know it's ready when the pasta is tender and about 1/4 to 1/2 cup of liquid remains in the pan.

Once your pasta is perfectly tender and has absorbed most of the broth, turn the heat down to low. Pour in the heavy cream and stir well to combine. Add the grated Parmesan cheese and shredded mozzarella, stirring continuously until everything melts into a velvety sauce that coats every piece of pasta. If the cheese looks grainy, your heat was too high, so make sure you're on low.

Turn off the heat completely and let the pasta sit uncovered for about 5 minutes. You'll notice the sauce thickens and clings to the pasta as it cools slightly. Right before serving, sprinkle fresh chopped parsley over the top.