Place the yeast, sugar, water and milk in the bread machine pan. Cover the liquid with the bread flour. Add the flour improver, salt and butter.

Set the bread machine to the dough setting. Press start.

Lightly oil one large baking sheet.

When the dough cycle has finished, remove the dough from the machine onto a lightly floured surface and gently knock back. Using your hands, shape the dough into a thick, short sausage shape and then, using a knife, cut it into 8 equal sized slices. Using your hands, gently roll out each disc of dough until it measures approx. 12 cm across. Dust the top of each round with some flour, using a sieve. Cover the dough with a sheet of clingfilm and leave in a warm place to rise for about 45 minutes.

Preheat the oven to 200°C/400°F/Gas 6. (reduce temperature for a fan oven)

When the baps are almost doubled in size, remove the cling film and sieve a little more flour over each of them. Bake the baps in the oven for about 15 minutes, or until the edges are golden and they are cooked through. Transfer the baps to a wire rack, cover them with a clean tea towel and leave them to cool.

To serve: split them open and fill them with a filling of your choice.