For the dough:
250g strong wholemeal flour
250g wholemeal khorasan (a.k.a. kamut) flour
75g dried currants
75g dried sultanas
25g fresh yeast
200ml skimmed milk
50g unsalted butter
75g coconut sugar
For the cinnamon filling:
30ml skimmed milk
2tsp coconut sugar
5tsp ground cinnamon
Preheat the oven at 100ºC / 175ºF / Gas Mark 1.
First, make the dough: Put the milk and butter in the microwave for a short burst just to melt the butter, and mix them well together. When it’s lukewarm, add the sugar and yeast. Set this mixture aside for the yeast to activate – it should get frothy while you work on the rest of the recipe.
Mix the flours and the dried fruit in a large bowl that can hold all of the dough ingredients. Make a well in the middle and crack the egg inside. Use a chopstick to mix the egg into the flour mixture; then add the milk, butter and yeast mixture, and continue mixing with the chopstick until you can start kneading. Fold the dough inwards, flattening it with your hands or with a round handheld silicone scraper, turn round a quarter of a turn, then fold inwards, and so on for about 10 minutes, or until the dough is soft, elastic and not sticky
Turn off the oven. Put the dough in a bowl that can hold double its current volume, cover it with a clean, damp (not wet) tea towel, and let it rise inside the warm oven for about an hour, until it’s doubled in size. Do keep an eye on it, as it can take more or less time to prove.
While the dough is proving, mix up the cinnamon filling: put the milk and butter in a ramekin and zap them in the microwave for 15-20 seconds, just enough to melt the butter. Add the sugar and the cinnamon powder, mix well and set aside, ready for when the dough is proved.
Prepare a sheet to roll the dough onto. You can use a sheet of greaseproof paper a bit bigger than 30x40cm, but it will be much easier to roll out and then roll up if you can get a silicone kneading mat.
When the dough has doubled its orginal size, get it out of the oven. Turn the oven on again to preheat to 175ºC / 330º F / Gas Mark 3/4. Roll out the dough onto the mat to form a rectangle roughly 30x40cm. Roll it out gently, trying not to knock too much air out of it. Brush all of the cinnamon evenly on the dough. Roll the dough along its longer edge.
Cut the rolled-up dough into slices about 3cm / 1 1/2in thick and arrange them on a baking tray so they barely touch, and let them prove again for another 15-20 minutes, as long as it keeps rising.
Bake it for 20-30 minutes, until it’s golden.