is just softened. Add arrowroot mixture and stir until thickened. Cool. To make the base and topping, blend together butter and sugar in a processor unti soft and fluffy. Add beaten egg, baking powder, ground almonds, flour and ground cinnamon and process until just crumbly. Turn mixture into a bowl. Grease and line a 23 cm springform pan. Turn out 2/3 of the crumble mixture onto a floured surface and knead gently together to combine. Use to cover base of prepared pan, simply pushing any cracks together. Spread cooled blackberry and apple mixture over base. Sprinkle reserved crumble mixture evenly over fruit topping and decorate with whole almonds. Bake at 350 F for 50 mins until pale golden. Serve warm or cold.