Preheat the oven to 200˚C, gas mark 6. Soak the cranberries in the apple juice for 30 minutes, then drain and toss into a bowl with the fruit, cornflour, cinnamon, sugar and vanilla.
Lay 1 filo sheet on the work surface and brush all over with melted butter. Lay another sheet on top and brush with more butter. Repeat until you have 7 layers of filo.
Scatter the pastry with the ground almonds, then pile the filling in an even line down the centre, leaving a wide border.Fold over the shorter pastry ends and brush with butter.
Tightly fold in the long edges, letting them overlap to enclose the filling. Carefully flip over and lay seam-side down on a baking tray lined with parchment. Brush with butter and bake for 25-30 minutes, until golden. Dust with icing sugar.