Preheat the oven to 180˚C / 200˚C Fan.
In a jug, dissolve the yeast with the warm water.
Sift together the flour, sugar, salt and cinnamon in a large bowl. Make a well in the centre and pour in the yeast mixture. Mix to form a dough, then turn out onto a lightly floured work surface and knead lightly until a smooth dough forms.
Work the softened butter into the dough one small piece at a time.
Once the butter is incorporated, sprinkle over the sultanas, currants and candied mixed peel until thoroughly combined.
Place the dough into a lightly greased bowl and cover with cling film, leave in a warm room until the dough starts to expand, about 30-60 minutes depending on warmth of the room.
Remove the dough from the bowl and push down to deflate.
Divide the dough into 40 g balls. Shape each piece into a smooth seam-free ball, then place onto a parchment paper-lined baking tray, evenly spaced apart to allow the buns room to expand.
Cover loosely with cling film and leave to rise in a warm room until doubled in size.
Meanwhile, mix together the cross ingredients then spoon into a piping bag fitted with a small round nozzle.
Once buns are well risen, pipe a cross across the top of each bun.
Bake in the preheated oven for 20 minutes or until golden brown.
While the buns are baking, make the syrup glaze. Add the sugar and water to a small pan and bring to a boil, just until the sugar dissolves.
While the buns are still hot, use a pastry brush to immediately apply the hot syrup and glaze them.
Transfer the buns to a wire rack, leave to cool completely, then serve.