Measure water into mixing bowl.
Add 1 tsp sugar and stir until sugar is dissolved.
Sprinkle yeast over water and let stand 10 minutes.
Stir well.
Add 1/3 cup sugar, salt, shortening, egg, mashed potatoes and half of flour.
Beat with a wooden spoon until smooth.
Add enough of remaining flour to make a soft dough that is easy to handle.
Mix very well with hand.
Turn out on floured board and knead until smooth and elastic and small bubbles appear under the surface.
Round up and put in greased bowl.
Grease top of dough, cover with a damp cloth and let rise in a warm place until double, about 1 1/2 hours.
Punch down, let rise again until nearly double, about 30 minutes.
Punch down again.
Grease a 10-inch tube pan with a solid bottom.
Pinch off bits of dough about the size of walnuts, shape into small balls, and dip each one into melted butter then roll in a mixture of the 3/4 cup sugar, orange rind, mace and pecans.
Put these balls of dough a little bit apart, in prepared tube pan, making 2 layers.
Sprinkle any remaining sugar mixture over top of dough.
Let rise until double, about 1 hour.
Heat oven to 5 degrees.
Bake 35 to 40 minutes or until coffee cake sounds hollow when tapped on top and is nicely browned.
Serve warm, breaking off little rolls as needed.