Preheat the oven to 180 °C.
Mix flour, oat flakes, sugar, butter and salt to a crumbly dough. Peel and core the apples and cut them into small cubes.
Mix the apples with lemon juice, lemon zest and the sugar. Butter the oven dishes well. Divide the apple mixture among the dishes. Sprinkle the crumbly dough on top.
Bake the appelcrumble in the preheated oven for about 30 minutes until golden brown.
In the meantime, whip the cream on yogurt starch until stiff.
Then serve the apple crumble still warm with the whipped cream.