German pancake / Dutch Baby

I recently came across a very delicious and simple recipe for breakfast/brunch or even dessert.  It is so easy and looks great all puffed up.  The first time I made it we just sprinkled it with powdered sugar but next time I'm going to try adding carmelized apples or pears.  It is just like the one you can order at The Original Pancake House (which is no longer in Boulder and I haven't checked the Denver location). 
German Pancake
1 cup flour
1 cup milk
6 eggs
1 tsp vanilla
1/4 tsp salt
1/2 cup butter
Preheat oven to 425 degrees.  Mix all ingredients except butter.  Melt butter in casserole dish and pour egg mixture into dish.  Bake for 20-25 min.