In a small bowl melt butter then pour into a 9x13 glass baking dish.
Place baking dish in oven and preheat oven to 400 degrees.
Using a whisk or a stand mixer, blend together eggs and flour together.
Mix on medium speed for 2 minutes.
Pour in milk and sugar and beat for 1 more minute on medium speed.
Open oven and pull out rack with the pan on it.
Gently pour in batter and bake for 25-30 minutes or until golden brown on the edges and the center is set.
Cut into 6 squares and serve immediately.