In a small bowl combine the flour, mixed spice, cinnamon and salt.In a separate larger mixing bowl, cream the butter and sugar in a mixing bowl. Add the egg yolk and lemon zest and beat until combined. Add the brandy and beat until combined.Add the flour mixture to the wet mixture and beat until combined.Beat until it turns into a breadcrumb consistency. Now use your hands to knead it into a dough. If it's too dry to hold shape, add a little milk.Add the dried currants and candied lemon peel. Use your hands to incorporate them into the dough.
Place the dough onto a sheet of parchment paper and roll it out to an even thickness of 1/4 inch.Use a 2 1/2 or 3 inch biscuit/cookie cutter to cut out individual biscuits. Gather up the leftover dough, roll it back out to 1/4 inch thickness, and repeat until all of the dough is used.Transfer the biscuits to a lined baking sheet.
Bake in the oven preheated to 350 F / 180 C for 10-12 minutes.Remove the biscuits from the oven and very lightly brush with the egg white.Sprinkle granulated sugar over the top. Brush one biscuit at a time, then sprinkle with sugar, then repeat for the other biscuits. This way the egg white won't begin to cook or dry out before you add the sugar (the egg white enables the sugar to adhere to the biscuit).Put the biscuits back in the oven and bake for another 6-8 minutes or until they're light golden.Let the biscuits sit for 3-5 minutes and then transfer them to a wire rack to cool.Store your Easter biscuits in an airtight container at room temperature. They will keep for up to 2 weeks. They can also be frozen for at least 3 months.Makes roughly twenty 2 1/2 inch Easter biscuits.