Hi, Steve,
I have used the pumpernickel recipe from Rose Levy Berenbaum's Bread
Bible with great success. It is even better if you throw in a
tablespoon or two of non-diastatic malt powder (or just diastatic
malt powder that has been sitting around for quite a while!). I
discovered this once by switching the measurements for gluten and
diastatic malt powder by mistake and continuing with the recipe
anyway (I added the additional gluten the recipe called for when I
realized the mistake, but there was no way to take out the extra malt powder).
Good luck!
Barbara