Place the butter in a 10-inch cast-iron skillet. Place skillet in a 400 degree F oven for 5 minutes or until butter melts and skillet is hot.
In a large mixing bowl, use a wire whisk or rotary beater to beat eggs. Add the flour, milk, granulated sugar, vanilla, and salt. Beat until mixture is smooth. Immediately pour batter into the hot skillet. Bake pancake for 22 to 25 minutes or until its puffed and well browned.
To serve, spoon fruit into center of warm pancake. Lightly sprinkle pancake with powdered sugar and serve immediately. Makes 6 servings.