Preheat the oven to 180c fan forced or 175c.
For the filling, place all the ingredients into a saucepan and bring to a boil. Boil gently for 10 minutes or until most of the liquid has been absorbed. Drop the heat and cook for a further 5 minutes. Allow the mixture to cool before filling the bases.
For the pastry, sift the flour and baking powder into a food processor and add the sugar, then the cubed chilled butter and pulse the mix until it resembles breadcrumbs.
Whisk the egg yolks with the tablespoon of water and add this to the flour and butter while pulsing until the mix just comes together.
Turn the mix onto a floured surface and bring together to form smooth dough, approximately 2 minutes. Press the dough into a flat disk and wrap with plastic film.
Refrigerate for at least 20 minutes or until firm to press. Roll the pastry onto a floured surface to a thickness of about 2-3mm. Cut out round or fluted bases to fit a standard muffin tin so that the pastry comes up about 1/2 way up the sides of the tin. You can use different cutters for the lids, stars, shapes or simply a slightly smaller size than the base.
Press the bases into greased tins and place a spoonful of the mix into each one, top with the lid, brush with a little egg white and bake for 18 minutes until golden.
Allow to cool in the tin before removing. Dust heavily with icing sugar to serve.
It will keep for at least 2-3 weeks in the fridge.