Combine eggs, milk, water, and salt in blender and blend until fluffy. Tap in flour a little at a time, beating until well blended.
Preheat empty 9×13 pan in oven for 3–4 minutes. Melt butter in preheated pan, pour in egg mixture, and immediately return to oven. Bake for 25 minutes at 425⁰F.
Brush with melted butter and dust with powdered sugar before serving