In a bowl, combine the flour, sugar, salt, and vanilla sugar. Gradually stir in the eggs, then slowly add the milk while continuing to mix. Add the melted butter.
Butter the dish, arrange the cherries, then pour in the clafoutis batter.
Bake for 10 minutes at 210°C, then lower the temperature to 180°C and bake for another 20 minutes.
Serve the clafoutis cold or warm, sprinkled with powdered sugar.