1. Preheat oven to 425 degrees. 2. Melt 2 TBS butter in a medium cast iron skillet then remove from heat. 3. In a blender mix eggs, milk, flour, salt, vanilla, and the sugar until smooth and foamy, about one minute . 4. Pour batter into skillet. 5. Bake until pancake is puffed and light brown, about 20 minutes. 6. Sprinkle with powdered sugar. 7. Serve immediately. Pancake may fall quickly.