Pull sour cherries in a small baking bowl with a third of the sugar and cherry brandy.
Melt the butter in a small saucepan, add the flour and mix both thoroughly and set aside.
In a saucepan, bring the milk to a boil with the remaining sugar and, after a short pause to cool, stir in the flour butter until the mixture thickens very slightly. Add the egg yolks and mix everything together. Whip the egg whites to egg whites and fold into the mixture together with the cherries. Pour the mixture into a buttered and sugared ovenproof dish with a capacity of about 1 liter.
Bake in the oven at medium heat, about 180`C, for about 25 minutes.