Begin by warming the milk in the microwave for around 90 seconds until it is hot to the touch, but not so hot that it boils.
Place the strong bread flour, golden caster sugar, cinnamon, mixed spice, salt and the fast action dried yeast into the bowl of your stand mixer, fitted with the K beater.
Make a well in the centre of the dry ingredients, before adding the warm milk and the egg.
Run the mixer until the ingredients start to clump together.
Add the butter and orange zest, and continue to run the mixer until the dough forms a single ball of dough.
Switch the K beater for the dough hook and use the mixer to knead the dough for around five minutes.
Stop the mixer and add the sultanas and dried apple to the dough, before continuing to knead for another five minutes.
Oil a large bowl and place the dough inside, before covering the top with cling film. Set the dough in a warm location and allow to proof for around one hour or until almost doubled in size.
Knock the dough back by punching into the top and then transfer the dough onto a lightly floured surface. Briefly kneed by hand, before dividing the dough into 12 equal portions.
Roll each portion of the dough into a tight ball before spacing them out evenly on a baking tray lined with a piece of greaseproof paper.
Lightly oil another piece of cling film and place this over the buns, before allowing them to proof for another hour.
While the buns are proofing, preheat the oven to 210°C/190°C Fan/Gas Mark 8.
Once the buns have finished proofing, it is time to add the crosses. Place the plain flour and the water into a bowl and mix until fully combined and smooth. Transfer the mixture to a piping bag, snip off the tip and carefully pipe the mixture across the tops of the buns to form the cross shapes.
Place the buns into the preheated oven and bake for around 20 minutes until golden brown.
While the buns are baking, combine the caster sugar and the boiling water in a bowl to make the glaze.
Transfer the buns to a cooling rack and use a pastry brush to brush the syrup all over the tops of your buns to give them their traditional shiny finish.