How to make
Put the soft butter in an oven dish with non-stick coating with a diameter of about 10″ (25 cm) and in a heated 390°F (200 °C) oven.
Beat the eggs lightly just to mix the egg yolks and whites. To them, add the milk, flour, sugar and salt, grated citrus rind and vanilla essence. Beat the mixture well and pour it into the oven dish with the melted butter that you've spread along the bottom and sides of the oven dish.
Put the German pancakes to bake for 15 minutes at 390°F (200 °C), then reduce to 340°F (170 °C) and bake for another 15 minutes. While you're baking the German pancake do not open the oven. When finished, turn off the oven, open the door slightly, and leave the pancake inside for another 10 minutes.
This is done to prevent a drastic change in temperature which would cause the pancake to deflate. Serve the pancake sprinkled with powdered sugar if desired, or garnish with honey and fruits.