Mix the flour with the yeast and a pinch of salt. Sift the flour and add the butter to form a dough. Mix the milk, coffee, molasses and a bit of sugar in a separate bowl. Add this mixture to the dough, work to blend, and spread the dough in a baking tin. Spread with butter and dust with cocoa powder and the remaining sugar. Roll it up to form a log and then cut into round slices. Place the slices cut-side down, and not touching one another, in a baking pan. Bake in a hot oven for about ten minutes.