Preheat the oven to 160ºC

Line the baking trays with parchment paper

Fit the K beater to the machine

Add Ingredients 1 (butter, sugar) into the Mixer bowl

Attach the Mixer bowl to the machine and fit the splash guard

Mix on speed 3 for 1 minute

Scrape down the sides of the bowl with a spatula

Add the first item of Ingredients 2 (egg yolk) into the Mixer bowl

Mix on speed 3 for 20 seconds

Add the remaining Ingredients 2 (flour, mixed spice, salt, currants, candied peel, milk) into the Mixer bowl

Mix on speed 1 for 30-40 seconds until a stiff dough formed

Transfer the dough to a lightly floured work surface

Roll out the dough into a circle

Using a round, fluted cutter, cut out biscuits

Transfer the biscuits to the prepared baking trays

Bake at 160ºC for about 10 minutes

Remove the baking trays from the oven

Brush the biscuits with the first item of Ingredients 3 (egg white)

Sprinkle with the second item of Ingredients 3 (caster sugar)

Bake at 160ºC for 5-10 minutes until light golden brown

Remove the biscuits from the oven

Turn out onto a wire rack

Let cool completely