Cook the pasta according to package directions. Drain and set aside.
1 pound dry penne noodles
In a skillet over medium heat, cook the ground beef until browned. Add sea salt, black pepper, and minced garlic. Stir and cook for 1–2 minutes until the garlic is fragrant. Set aside.
1 pound ground beef, 1 teaspoon sea salt, ½ teaspoon black pepper, 2 cloves garlic
In a large pot oven safe pot or Dutch oven, melt the butter over medium heat. Whisk in the flour and cook for 1–2 minutes to form a roux. Slowly whisk in the warm milk, stirring continuously to prevent lumps. Cook until the sauce thickens. Season with salt, black pepper, cinnamon, and cardamom.
1 stick, ½ cup all-purpose flour, 6 cups warm whole milk, 1½ teaspoons sea salt, ¾ teaspoon black pepper, ½ teaspoon cinnamon, ½ teaspoon ground cardamom
Reserve 1½ cups of the béchamel and set aside. Add the pasta and ground beef to the remaining béchamel in the pot and stir until well combined. Top with the béchamel sauce
Bake at 425 degrees for 15 minutes or until the top is bubbly and brown (you can also broil for 1-2 minutes just to get the top to brown but be very careful because it can burn very quickly).