Preheat your oven to 356°F.
Grease your baking dish with the butter. Pit the cherry, if needed, and arrange them in your dish.
Whisk together the eggs, sugar, salt and half of the flour. Add half of the milk and whisk well. Add then the remaining of flour and milk gradually. Make sure to mix well to avoid lumps and until you have a smooth batter. You can add the kirsch here if you want.
Pour the batter over the cherries. Bake for about 40 minutes (might need a bit more baking if you removed the pits) or until golden.
Dust with powdered sugar.