- Combine sugar, cocoa, yeast, cinnamon, 450g of the flour and salt in the bowl of an electric mixer fitted with a dough hook and mix on low speed to combine. Heat milk and butter in a small saucepan over low heat until butter melts, cool to lukewarm, then whisk in egg. Add milk mixture to flour mixture and knead until smooth and elastic (8-10 minutes; dough will be quite soft). Add sultanas, chocolate and candied orange, knead to combine, then transfer dough to a lightly buttered bowl, cover and stand in a warm place until doubled in size (50 minutes to 1 hour).
- Knock back dough, divide into 12 even pieces, then roll each into a smooth ball. Arrange in three rows of four on a large baking tray lined with baking paper, leaving approx. 1.5cm between each for ball to expand. Cover with a tea towel and stand in a warm place until doubled in size (30-40 minutes).
- Preheat oven to 220 °C (430 °F). Stir remaining flour, sunflower oil and 50 ml cold water, adding a little more water if necessary to achieve a smooth paste. Spoon into a piping bag fitted with a small plain nozzle and pipe a cross on each bun. Bake for 10 minutes, then reduce oven to 180 °C (350 °F) and bake for another 8-10 mins or until buns are golden brown and sound hollow when tapped (or when their bottom is springy). Do not open the oven door during the baking.
- For cinnamon glaze, stir sugar, cinnamon and 50ml water in a small saucepan over medium-high heat until sugar dissolves, bring to a simmer, then cool briefly to thicken a little (5 minutes). Brush warm buns with glaze and serve.
Note: I have put my dough to rise in closed oven at about 50°C (120 °F) max.