Preheat the oven to 400F.

In a blender, combine the eggs, milk, flour, vanilla and salt; cover and process until smooth.

Place cast-iron skillet over medium heat and stir butter until melted. Continue to cook, slightly simmering, until butter foams, stirring often. Once butter forms toasty brown bits, becomes a golden caramel color, and has a warm nutty aroma, pour in the batter.

Cook for 3-5 minutes and bake in the oven until puffed and golden brown, about 25-30 minutes more.

Add lemon juice to pancakes and sift the confectioners' sugar over the pancake.

Serve immediately in the skillet with maple syrup or your favorite fruits or jams.