For the tartlet casings:
Preheat the oven to 150ºC. Grease 6 small, fluted tart tins. Combine the coconut, sugar and egg whites in a bowl. Divide and press the mixture into the tins and bake for 30 minutes or until golden. Leave to cool.
To make the filling:
Use an electric beater to whip the mascarpone, fresh cream and sugar in a mixing bowl until it starts to thicken and look glossy and smooth. Carefully fold in the vanilla seeds and lemon zest. Fill the cooled macaroon casings halfway with the cream mixture and drizzle over some of the coulis. Cover with some more of the cream and finish off with fresh berries. Dust with icing sugar and serve.