Place the flours and sugar into a bowl. Using a box grater, grate the butter into the flour. Add the iced water and vanilla and use your fingertips to mix until a soft dough forms. Cover and refrigerate for 30 minutes or until firm.
Roll out pastry between sheets non-stick baking paper to a rough round that is approx. 4mm thick. Place onto a baking tray refrigerate until firm.
Preheat oven to 180°C.
To make the almond filling, place the almond meal, orange rind and sugar into a bowl and mix to combine. Sprinkle the almond filling over the pastry leaving a 5cm border.
Top the almond filling with the plums and fold over the excess pastry to form and edge. Sprinkle the plums and pastry with the demerara sugar. Bake for 40–45 minutes or until the pastry is crisp and golden. Serve the tart warm or cold with vanilla bean yoghurt or ice cream.
