Heat the oven to 375 degrees. Brush the baking dish with melted butter and dust thoroughly with sugar. Set remaining butter aside.
Saute the cherries with a tablespoon of sugar and the butter until the cherries have been carmeralized. Line the cherries in the baking dish.
Whisk the sugar, salt and the eggs together until frothy. Sift in the flour and stir just until well blended.
Pour the milk and a knob of butter in a pot and bring it to the boil. Add the milk into sugar and eggs mixture a ladle at a time and combine thoroughly. It will look like the batter of crepe.
Strain the batter into another bowl, then pour it over the cherries.
Bake in a moderate oven, 375°F for about 30 minutes in a waterbath. The dish is cooked when the centre is just firm when you press lightly with your finger tips. The top should be golden brown and the edges rise slightly.
Cool for a few minutes. The clafoutis will deflate within a minute. Dust with confectioner’s sugar if desired. Serve warm.