Soft, fluffy sourdough cinnamon rolls that stay moist for days. The dough is nurtured overnight, then rolled with a buttery cinnamon filling, proving to be a delightful breakfast or snack.
In a large mixing bowl, combine the milk, sourdough starter, sugar, whole wheat flour, bread flour, egg and salt. Stir until the mixture is uniform and a shaggy dough forms.
Add the cold cubed butter a few pieces at a time, kneading gently until the butter is fully incorporated and the dough feels smooth, supple and slightly glossy.
Cover the bowl with plastic wrap or a clean kitchen towel and let the dough rest at room temperature for about 30 minutes. Then refrigerate it on the top shelf of the fridge for an overnight fermentation – roughly 12 hours.
The next morning, remove the dough from the fridge and allow it to come to room temperature for about 2 hours before shaping.
While the dough warms up, make the filling. In a small bowl, beat together the soft butter, granulated sugar and ground cinnamon until you have a smooth, creamy spread.
Lightly flour a work surface, roll the dough into a rectangle about 1 cm thick. Spread the cinnamon‑butter mixture evenly over the surface, then roll the dough tightly into a log. Using a sharp knife or bench scraper, cut the log into equal pieces and place the buns on a parchment‑lined baking sheet, leaving plenty of space between them.
Cover the shaped buns loosely with a kitchen towel and let them proof for about 3 hours, or until they have visibly puffed up.
Preheat the oven to 190 °C (fan‑forced). In a small cup, whisk together the egg yolk and a splash of milk, then brush the tops of the buns with the glaze.
Bake the buns for 20–25 minutes, or until they turn a beautiful golden‑brown colour. Remove from the oven and let them cool on a wire rack before enjoying – they taste best once they’re fully cooled.