For the dough
• 500 g plain flour
• 75 g sugar
• ½ tbsp ground cardamom
• 1 sachet (7 g) dried yeast
• ½ tsp salt
• 80 g butter
• 200 ml milk
• 1 egg

For the filling
• 250 g frozen blueberries
• 100 g soft butter, at room temperature
• 50 g sugar
• 2 tbsp ground cinnamon

To glaze
• 1 egg, beaten

Icing
• 100 g icing sugar
• 1–2 tbsp water

Thaw the blueberries in a bowl. You can drink the juice that collects as they thaw – it’s delicious!

Mix the yeast with the flour, sugar, salt and ground cardamom. Melt the butter and stir in the milk. Add the butter and milk mixture and the egg to the flour mixture. Mix everything together, then knead the dough for about 15 minutes.

Cover the dough with a clean tea towel and leave to rise at room temperature for about 30–40 minutes.

For the filling, mix the softened butter with the cinnamon and sugar.
Roll out the dough into a rectangle about 3 mm thick and 30 cm wide. Spread the butter mixture evenly over the dough, then scatter three-quarters of the thawed blueberries over the top.

Roll the dough up tightly and cut the roll into 20 slices. Arrange the buns in one or more baking dishes lined with baking paper. Scatter the remaining blueberries over the buns.

Cover with a clean tea towel and leave to rise for about 30 minutes, or until the buns have doubled in size.

Preheat the oven to 200°C (400°F).

Beat the egg and lightly brush it over the buns. Bake for about 15 minutes, until golden brown.

For the icing, mix the icing sugar with a little water, adding it gradually until you have a smooth icing. Once the buns have cooled, drizzle the icing over them.