- Make the brandy butter by creaming the butter with a wooden spoon in a bowl and adding the sifted sugar and other ingredients. Work everything together with your fingers, transfer to a bowl, and cover. Leave to firm in the fridge, where it will keep for three or four days.
- Preheat the oven to 200ºC. To make the pastry, put the butter, flour, sugar and salt into a processor and pulse a few times. Add two tablespoons ice-cold water and pulse a few more times, until it comes together.
- Grease the holes of a 12-hole muffin tin. Make 12 walnut-sized balls of pastry and press into the tin with your fingers. Stir the Cointreau or triple sec, into the mincemeat and spoon the mincemeat into the pies. Make slightly smaller balls of pastry and pat them out to make lids, (you can cut out star shapes for the lids if desired) pressing the edges together to seal. Brush the surfaces with the beaten egg, and bake for 20 minutes, until lightly golden.
- Allow to cool for a few minutes, then transfer to a wire rack to cool properly. Warm through, if you like, before serving, and dust with icing sugar. Eat with lots of brandy butter.