Preheat the oven to 230°C/450°F/Gas mark 8. Slice half of the apricots and set aside. Dice the remaining apricots.
Combine the cream, flour, caster sugar and diced apricots in a large saucepan. Bring to a simmer over a medium heat and cook, whisking until thick, for 3 minutes. Remove from the heat, add the Kirsch, then whisk in the egg yolks one at a time.
Beat the egg whites in a mixing bowl until stiff.
Butter a small soufflé dish and dust with caster sugar. Spread 50g/2oz of the apricot mixture on the bottom. Add about a third of the egg whites to the remaining apricot mixture. Gently fold together. Carefully fold in the remaining egg whites in two batches. Spoon over the apricot mixture in the soufflé dish. Bake for 12–15 minutes until lightly browned on top. Dust generously with icing sugar, and arrange sliced apricots on top. Serve immediately.