Brown the ground beef, onion, and 1/2 tsp salt in a large skillet over medium-high heat until the meat is no longer pink, about 6 to 8 minutes. Stir in the garlic if using, cook 30 seconds, then drain excess fat.

Move the beef mixture to a bowl. In the same skillet over medium heat, cook the cabbage, remaining salt, pepper, garlic powder, and 2 tbsp of broth until wilted, about 5 to 7 minutes.

Reduce heat to low, return the beef to the skillet, and stir in the cream cheese, sour cream, remaining broth, and cheddar. Cook, stirring, until the sauce is smooth and coats the cabbage, about 3 minutes.

Preheat oven to 350°F. Spread the mixture into a 9x13-inch baking dish. Toss the crushed Ritz crackers with the melted butter and sprinkle over the top. Bake uncovered for 20 to 25 minutes until bubbly and golden. Rest 5 minutes, then serve.