For the dough, place the flour, sugar and yeast in the bowl of a freestanding electric mixer fitted with a dough hook.
Pour the milk and 100ml/3½fl oz water into a saucepan and add the butter. Heat until the butter is melted. Check the temperature: it should be lukewarm to activate the yeast. Pour the milk mixture over the dry ingredients with the dough hook slowly turning. ‘Knead’ in the machine for about 5 minutes, until a smooth dough has formed.
Brush a mixing bowl with some oil and place the dough into the bowl. Cover with cling film and leave to rise in a warm place: this will probably take about 2 hours. You can leave it in a cool oven (40C Fan) if your oven has a dough rising function and this should take about 1 hour.
When the dough has doubled in size, place on a lightly floured surface and ‘knock back’ by kneading by hand for a few minutes to release the air. Butter a 23cm/9in round springform tin.
To shape, roll the dough out to a rectangle. Sprinkle the blueberries, orange zest, ground cinnamon, nutmeg and brown sugar over the dough. Starting at a long end, roll up the dough (like a Swiss roll). Slice into 10–12 swirls using a sharp knife. Transfer to the buttered tin with the swirls arranged cut-side up.
Brush with oil and place in a warm place to rise for about 30 minutes, or until doubled in size again
Preheat the oven to 200C/180C Fan/Gas 6.
Brush with egg wash and bake for 20–25 minutes, or until golden-brown and cooked through. Place on a wire rack to cool.
Mix together the icing sugar and lemon juice (or water) in a bowl to form a paste and drizzle over the top of the swirls. Scatter over the candied nuts and enjoy.