Make the hot cross bun dough: in the bowl of a mixer (see notes), add flour, salt and sugar and combine, then add five spice, cinnamon, cardamom, vanilla extract, and orange zest to the flour. Thoroughly combine to distribute the salt in particular, as it can inhibit the yeast activation.
Mix on a slow speed for 3 to 4 minutes, adding the cubes of butter, piece by piece, to ensure the butter is well distributed. When the dough has come together, easily comes off the sides of the bowl and sticks to the dough hook, the dough is ready. It should look wet and glossy.
Add the fruit and knead the dough: Coat the palms of your hands with oil or flour, then place the dough on a floured workbench. Spread the dough out and sprinkle the dried and candied fruit on the dough. Gently knead the dough to mix the fruit through the dough for a couple of minutes.
Prove the dough: Place the dough in an oiled bowl and cover with cling-wrap oiled on one side, being the side that might contact the dough as it rises. Prove for about 1½ – 2 hours in which time the dough should double.
Once the dough has doubled in size, place the dough on a lightly floured workbench, and knock the dough back to expel the air.
Divide the dough into pieces: separate the dough into 6 equal pieces that weigh around 100g each, then prepare a large baking tray lined with parchment paper.
Create the bun shape: flatten each dough piece roughly and pick up a corner of the dough and press it into the middle of the dough. Repeat until you have formed a tight ball. Turn the dough ball over, which should reveal a smooth, taught surface.
Prove the buns: place the finished buns evenly-spaced on the baking tray; lightly cover them with the oiled cling-wrap, and leave to prove the buns for one hour.
Preheat the oven to 200°C while the buns are proving.
Brush the buns with an egg wash: using a pastry brush, brush each bun with an egg wash made from a beaten egg and a little salt.
Create the cross paste: to a small mixing bowl, combine the ingredients for the paste; as the paste needs to be piped, a good firm consistency is best. Place the mix in a piping bag and mark the crosses.
Bake the buns: bake the hot cross buns for around 15 minutes, rotating the tray halfway through cooking. When the buns are a golden brown colour, they're ready.
Allow the buns to cool: slide the tray out of the oven and transfer the hot cross buns to a wire rack to cool.
Serve the hot cross buns: spread on lashings of good quality butter. Any leftover hot cross buns can be toasted and buttered.