– eggs – milk – all-purpose flour – sugar – vanilla extract
Set the oven to 220°C (425°F) and place a cast-iron skillet or any oven-safe pan inside to heat thoroughly. In a blender or using a mixer, beat the eggs until frothy.
Add the milk, flour, sugar, vanilla extract, and salt, blending until the batter is smooth with a thin, pourable consistency.
Carefully take the hot skillet out of the oven and add the butter, letting it melt and coat the bottom and sides of the pan.
Quickly pour the batter into the skillet with the melted butter, then return it to the oven.