Mix the flour with all the other ingredients up to and including the salt. Add the butter, honey, espresso and water, knead for approx. 10 mins. to form a soft, smooth dough. Cover and leave to rise at room temperature for approx. 2 1/2 hrs. until doubled in size.
On a lightly floured surface, roll out the dough to a 30 x 40 cm rectangle. Cut the dough crosswise into five strips and lengthwise into six strips. Stack the rectangles on top of each other, transfer to the loaf tin, sprinkle with oat flakes. Cover and leave to rise for a further 30 mins.
Approx. 40 mins. in the lower half of an oven preheated to 180°C. Remove from the oven, allow to cool a little, remove from the tin and leave to cool on a rack.