Simmer mincemeat ingredients in a large pan over low heat for 10 minutes until combined.
Remove from heat, cool, and stir in your choice of brandy, rum, or sherry.
Preheat oven to 200°C and grease a 23x33cm tin.
Rub butter into sifted flour and icing sugar until it looks like coarse breadcrumbs.
Mix in enough cold water to form a firm dough and chill for 30 minutes if possible.
Roll out pastry on a floured surface to line the base and sides of the prepared tin.
Spread the cooled mincemeat mixture evenly over the pastry base.
Melt and slightly cool the butter for the topping.
Mix remaining topping ingredients with the melted butter to form a dough and chill.
Grate the chilled topping over the mincemeat and spread it out evenly.
Bake for 20-25 minutes until the top is golden-brown.
Cut into 16 slices and serve warm with cream or brandy butter.