Preheat oven to 400°F (200°C). Heat olive oil in a skillet over medium heat. Add ground beef, onion, and salt.
Cook for 8–10 minutes until browned and onions are soft. Drain excess fat if needed. Stir in Worcestershire sauce and cook 2 minutes more.
Spray a 9-inch pie plate with nonstick spray. Spread the beef mixture evenly into the dish.
In a bowl, whisk eggs, buttermilk, and melted butter until smooth. Add flour and baking powder; whisk until fully combined.
Pour the batter over the beef. Sprinkle shredded cheddar evenly across the top.
Bake for 25 minutes, or until golden brown and set in the center. A toothpick inserted should come out clean.
Let cool for 5–10 minutes. Slice and serve warm with pickles, ketchup, or burger sauce.