Measure out the flour into a big mixing bowl. Slowly whisk the milk in, followed by the salt, eggs, cinnamon, vanilla extract and sugar. Whisk everything until it's a smooth mixture.
Lightly oil a griddle/frying pan, then bring it up to medium heat.
Soak the bread slices in the flour mixture until they're completely saturated. Cook the bread on each side until they turn golden brown. Enjoy while it's still hot!