In a mixing bowl, combine the flour, cornstarch, salt, and sugar. Add the beaten eggs.

Gradually add the milk while whisking, then add the vanilla extract. Whisk vigorously (by hand or with a mixer) until smooth. If there are lumps, use an immersion blender to blend until smooth.

Heat your crêpe pan and lightly grease it with sunflower oil. Pour a ladleful of batter onto the pan and cook each crêpe for 1 to 2 minutes on each side.

Repeat until all the batter is used.