In a large bowl mix together the flour, cocoa powder, mixed spice, salt and yeast. In a pan heat together the butter and milk gently until the butter is melted and the mixture is lukewarm.
Make a well in the middle of the dry ingredients and slowly pour half the butter and milk mixture. Mix this together and then add the beaten egg. Mix this again, followed by the remaining butter and milk mixture. Mix with your hands to form a soft dough.
Either tip this onto a lightly floured surface and knead by hand or you can use a stand mixer with a dough hook attachment. Knead the dough for 10 minutes until smooth, soft and elastic.
Lightly oil a bowl and place the dough into it. Cover with clingfilm and allow it to prove for 1 hour in a warm place, or until it has doubled in size.
After an hour, remove the clingfilm and knock the air out of the dough. Tip it onto a lightly floured surface and add the chopped chocolate, raisins and citrus peel by stretching and folding the dough to incorporate, making sure the fruit is evenly distributed throughout. Now divide the dough into 12 equal size balls. Shape them by rolling between your palm and the surface so they are smooth and even. Place the balls onto a baking tray lined with baking paper and space them with roughly 2 – 3cm gap between them.
Loosely cover the tray with clingfilm and leave again in a warm place for 45 – 60 minutes until they have doubled in size again. They should be puffed up and just touching. Preheat the oven to 200C.
Make the flour mixture by mixing together the plain flour, olive oil and water. Beat together until it forms a smooth paste and then transfer into a piping bag.
Once the buns have proved and risen, carefully remove the clingfilm. Pipe the crosses across the top. Then place into the middle of the oven and bake for 15 – 20 minutes until lightly golden brown.
Remove from the oven and brush the tops with golden syrup so they are glistening and then sprinkle with Maldon salt. These buns are best served slightly warm so the chocolate chunks are oozy and melted.