German Baby

Preheat oven to 425 degrees F (220 degrees C). Place butter in a 10 inch cast iron skillet and heat the skillet in oven.
Beat eggs at high speed with an electric mixer. Slowly add the milk and flour.
Pour batter into hot skillet. Return skillet to oven and bake for 20 minutes. It will rise like a souffle, then fall when taken out of oven. Lightly dust with powdered sugar and serve.