Grease and dust a 12-cupcake tray, set aside. For the sweet pastry, in your Kenwood bowl, using the K-Beater, cream the butter and sugar together until pale in colour. Add the egg and vanilla, combine.
Finally, add the flour. Do not over mix at this stage. Turn the mix out onto a floured surface, gently knead to form a ball, wrap in cling and chill for a minimum of 30 minutes.
Once rested, return to the floured surface and roll out. Cut out 12 x 10cm circles and place one into each cupcake case, press up the sides. Divide the mincemeat between the 12. (Any excess pastry can be chilled or frozen for use another time).
For the biscuit topping, in the Kenwood mixing bowl fitted with the K-Beater, cream the butter, vanilla and icing sugar together until pale and soft. Add the sieved flour and cornflour to this, and mix well. Spoon this batter into a piping bag fitted with a medium star shaped nozzle and pipe on top of the mincemeat filling. This will spread slightly so when piping, so don't cover the top completely.
Bake at 170oC (150 oC fan/ 325oF/ Gas 3) for 25-30 minutes or until golden brown. Once baked, allow to cool for ten minutes before removing from the tin.
Best served warm with a spoon of semi whipped cream!