In a food processor: blend together the first 4 ingredients. Add in the butter and pulse until a crumbly texture is achieved. Add in the egg and almond extract and blend until a smooth dough forms.
By hand: in a bowl, stir together the first 4 ingredients. Add the butter to the bowl and rub into the dry ingredients using your fingertips until a crumbly texture is achieved. Add the egg and almond extract, stir/knead together until a smooth dough forms.
Wrap the dough in plastic wrap and chill for at least 4 hours (it's quite soft dough, so it's easier to handle when it's cold).
Preheat your oven to 180 C (350 F). Roll the chilled pastry out on a floured piece of parchment paper, using a well floured rolling pin. It should be about about 1/8-inch (3 or 4 mm) thick. Cut into circles (the size of them depends on your tartlet/pie tin. Normally it's around 2.5-inches or 7 cm diameter). Line each cavity of the pie tin with a circle of pastry. Fill with a heaped teaspoon of mincemeat. Re-roll the scraps of pastry and cut out stars for the tops. Top each pie with a star of pastry.
Brush with cream or milk and sprinkle with demerara sugar.
Bake for 15-20 minutes until golden brown around the edges. Dust with powdered sugar.
Serve them warm, with tea. Or cream. Or BOTH.