Roll the pastry out thinly on a lightly floured surface, then stamp out 12 × 10 cm (4 inch) circles with a fluted biscuit cutter and press into a buttered 12-section muffin tin, rerolling the pastry trimmings as needed. Prick the bases 2–3 times, then chill for 15 minutes.
Bake the tarts blind (see
Meanwhile, mix the cornflour and the measurement water to a paste in a saucepan, add the apples, sugar and cook for 10 minutes, stirring from time to time, until the butter and apples are soft. Leave to cool for 15 minutes, then loosen the tarts and remove from the tin.
Spoon the apples into the tart cases. Whip the cream to form soft swirls. Fold in 2 tablespoons sugar, spoon over the tarts and sprinkle with the remaining sugar. Serve cold.