Punch dough down and transfer to an oiled surface. Using a rolling pin, roll the dough into a 16 x12 inches (40x30cm) rectangle.
With the back of a spoon or a spatula, spread 2 tablespoons (30g) softened butter over two thirds of the rolled dough. Fold dough like a letter into thirds, starting with the unbuttered side of the rectangle. Rotate the dough 90° and repeat rolling the dough into a 16 x12 inches (40x30cm) rectangle.
Again, spread 2 tablespoons (30g) softened butter over two thirds of the rectangle. Fold dough like a letter into thirds, starting with the unbuttered side of the rectangle.
Cut the dough into 8 equal pieces. Twist each piece and bring the ends together, pinch the ends and place on a parchment paper baking sheet.
Cover with a kitchen towel and let rise for 20-30 minutes.
Meanwhile, preheat the oven to 400F (200C).
Brush the buns with beaten egg and sprinkle sesame or poppy seeds on top.
Bake for 15-18 minutes or until puffed and golden brown.