Place your tablespoons of butter in your dish (9x13 if you want a thinner pancake, 9x9 if you want it thicker... You can also use a cast iron skillet) and allow the butter to melt in the oven as it is preheating.
During this time you will go ahead and mix together your eggs, milk, flour, salt, and vanilla in a blender until smooth. Pour batter into the baking dish, over melted butter.
Bake, for approximately 25 minutes or until edges are golden brown and puffed up.
It is of course optional but we enjoy these served with a little powdered sugar and pancake syrup.