Moravian Sugar Cake

Combine sugar with potatoes, mashing to dissolve. Dissolve yeast in the water and add to the potato mixture. Stir in the salt, lard and eggs. Add flour and mix until smooth. Cover and let rise for 5 or more hours (or overnight). Spoon batter 1/2" deep into two greased 13x9" cake tins. Let them rise for an hour, until puffy. Poke indentations 1" apart into the surface, but not too deep. Put chips of cold butter in the holes, and push down with some brown sugar (these are called butter holes). Sprinkle the rest of the brown sugar on the surface, and lightly with cinnamon. Bake at 350F / 180C for 25 minutes. Let cool in the tins for 5 minutes before removing.