The homemade candied orange peel in these buns is well worth the effort – it’s tender and succulent.
Make the dough. Put the milk in a heatproof jug, add the butter and warm in the microwave on full power for about 15–20 seconds, until the butter is almost melted (or, do this in a small pan over a low heat).
Pour the mixture into the bowl of a stand mixer fitted with the dough hook. Add the remaining dough ingredients and mix together on a slow speed for about 7 minutes, until the dough is smooth and elastic. Cover with cling film, then leave to rise for about 1 hour, or until the dough has doubled in size.
Meanwhile, make the filling. Put the sultanas and the brandy in a small pan over a low heat. Heat for 1–2 minutes, until the sultanas are plumped up, then pour them into a bowl with any remaining brandy and allow to cool.
Peel the orange quarters and cut the peel into 5mm-wide strips (reserve the flesh to juice for the icing). Put the strips into a medium pan, add water to cover well, then place over a high heat and bring to the boil. Boil for about 10 minutes, until the white pith becomes translucent. Change the water and boil for another 10 minutes; then change and boil once more.
Drain the peel through a sieve. Rinse out the pan, add the caster sugar and 150ml of water. Heat gently until the sugar dissolves, then add the softened peel. Bring to the boil, allow to boil for 5 minutes, then remove from the heat and drain the peel through a sieve again, reserving the syrup. Once the peel is cool, cut it into 5mm dice. Combine the brown sugar and spices in a small bowl, and set aside.
Tip out the risen dough onto a floured work surface, and punch out the air. Roll out the dough into a large square of about 35–40cm. Preheat oven to 200°C/180°C fan/400°F/Gas 6.
Spread the 50g of softened butter over the dough. Sprinkle over the sweetened spice mixture, then gently press it down with your hands. Scatter over the sultanas and candied peel.
Take the edge closest to you and roll up the dough as tightly as you can. Trim the ends and cut the roll into 12 equal pieces along its length. Place the pieces in the buttered pan, cut-side up, to form 3 rows of 4. Cover with cling film and leave for about 1 hour, or until risen to the top of the tin. (When the dough is ready, it should spring back when lightly touched.)
Bake the buns for 20 minutes, until the tops are golden brown. Remove from the oven and leave the buns to cool in the tin for 15 minutes, then turn out as one piece onto a wire rack. Warm a little of the reserved candied orange syrup and brush this over the buns, to glaze.
To make the 20-second icing, mix the icing sugar with 1–2 teaspoons of juice squeezed from the reserved orange quarters. Test the consistency by dropping a blob of icing onto the surface of the rest – it should take about 20 seconds (hence the name) to meld back into the rest of the icing. Place the icing in the piping bag, snip off the end and drizzle in diagonal lines over the buns.