1.Preheat the oven to 180°C (160°C fan-forced). Generously grease four 8cm-round, loose-based flan tins; place on oven tray
2.Cut the pastry into quarters. Ease the pastry into the tins; press into side, trim edges with a knife. Line the pastry with baking paper; fill with baking weights or rice. Bake cases for 10 minutes. Remove paper and weights; bake for about a further 5 minutes or until golden brown. Cool.
3.Meanwhile, combine the quince paste and juice in small saucepan over low heat. Stir until the paste and juice are well combined.
4.Combine mascarpone, rosewater and 1 tablespoon icing sugar in a small bowl. Spoon the mascarpone mixture into the tart cases. Drizzle with the cooled quince paste; dust with sifted extra icing sugar.