1. Make the bun dough: sift the flours and yeast into a bowl. Add a small pinch of salt. Stir in the sugar. Chop the butter into a pan and gently heat till it’s melted. Stir in the cold milk – this should give you a hand-hot mixture. If it’s a bit too cold, put back on the heat for a few secs.
2. Beat the egg and add it to the flour bowl. Pour in the warm milk and butter. Use your hands to mix it together to form a soft dough. Sprinkle your work surface with a little extra flour and turn the dough out. Knead for around 3-4 mins till the dough is smooth and elastic – don’t keep adding flour, as this will make the dough dry. Keep kneading, even if it sticks – a sticky dough is better than a dry one.
3. Scrape the dough back into the bowl. Cover with a clean tea towel and leave somewhere warm for 2 hrs till the dough has doubled in size.
4. While the dough rises, make the filling: zest and juice the orange. Tip the cranberries into a bowl. Add the orange zest and half the juice (save the rest for later).
5. Whisk the egg yolks with the caster sugar in a bowl. Slowly whisk in the spelt flour till the mix is smooth. Warm the milk in a pan over a medium heat till it just comes to the boil, then slowly whisk it into the egg yolk mixture. Whisk in the mixed spice. Pour it all back into the pan and simmer for 2-3 mins, whisking, till it thickens. This is your crème patisserie. Cover with cling film and set aside.
6. Tip the dough out of the bowl and punch it down to flatten a little. Knead for 2-3 mins so it’s smooth and supple. Dust your work surface with a little extra flour and roll out the dough to make a rectangle around 25cm x 40cm. Spread the crème patisserie over it, then spoon the cranberries over the top. Roll up from the long side to make a nice, tight cylinder. A little filling out might fall out the ends.
7. Slice the cylinder into roughly 12 buns. Butter a large baking tin or dish and nestle the buns in there. Cover with a tea towel and leave somewhere warm for 30 mins till they’re risen and puffy. While they’re rising, heat your oven to 180°C/Fan 160°C/Gas 4.
8. Brush the buns with a little milk to glaze them. Bake for 20-25 mins till the buns are risen, golden and firm to the touch. While they cook, stir the remaining orange juice into the icing sugar to make a thin glaze. When the buns come out of the oven, cool them for a few mins in the tin, then turn out onto a wire rack. Drizzle over the orange glaze. These are best eaten fresh, so serve them the same day they’re baked.
9. Tip: You can make the dough the night before and let it slow rise overnight in the fridge. You can also make the crème patisserie and keep that in the fridge too, then assemble the buns in the morning. If the dough is cold, the second rise will take longer, so make sure you put them somewhere nice and warm to encourage them along.