Make the dough

• Mix the flour, sugar, yeast and salt in a bowl.
• Add the lukewarm milk and a little soft butter, then knead into a smooth dough.
• Cover and let rise until doubled in size.

Laminate with butter

• Roll the dough into a rectangle and dot with the cold butter.
• Fold the dough over the butter, roll out and fold again, repeating a few times.
• Chill the dough between folds so the butter stays cold.

Cook the blueberry filling

• Simmer the blueberries with the sugar, cornstarch and lemon juice.
• Stir until thick and glossy, then let cool completely.

Shape the buns

• Roll the chilled dough out and cut into squares.
• Spoon the blueberry filling into the centre of each square.
• Fold the corners over the filling and press to seal, then place on a lined baking tray.
• Brush with the beaten egg and let rise again.

Bake

• Bake in a preheated oven at 190 °C until deep golden brown.
• Transfer to a cooling rack.

Glaze and finish

• Whisk the cream cheese with the powdered sugar and a little lemon juice into a smooth glaze.
• Drizzle over the cooled buns.