Lift the bread pan out of the machine and fit the blade. Put the ingredients in the pan, following the order specified in the manual.
Fit the pan into the machine and close the lid. Set to the dough programme. Thoroughly butter a 750 ml (1¼ pint) brioche mould or a 1 kg (2 lb) loaf tin.
At the end of the programme turn the dough out on to a floured surface and cut off one quarter. Shape the larger piece into a ball and drop it into the brioche tin. Push a deep, wide hole into the dough with your fingers. Shape the remaining dough into a ball and press it gently into the indented top. (If you are using a loaf tin shape the dough into an oval and drop it into the tin.)
Cover loosely with oiled clingfilm and leave to rise in a warm place for 50–60 minutes or until almost doubled in size. Mix the egg yolk with 1 tablespoon water and gently brush over the dough. Bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 20–25 minutes or until deep golden and firm. (Cover the loaf with foil if the crust starts to over-brown.)
After baking leave the bread in the tin for a few minutes, then shake out on to a wire rack to cool.