Preheat oven to 425. Put butter in 9x13 glass baking dish & place in oven while preheating. Put the eggs in a blender & mix for 1 minute. Slowly add milk & then add flour, mix until well blended. Open oven & swirl the melted butter around the bottom of the dish until completed coated. Pour batter in dish & bake until golden brown 15-17 minutes.