Scald milk. Add shortening, cool to lukewarm. Dissolve
yeast in warm water. Add yeast, sugar, eggs, warm
mashed potatoes, and salt to milk. Beat in half of flour.
Add remaining flour (it will be sticky). Let rise until
double. Dump on well-floured board and knead minimal
amount. Divide into fourths for easier handling. Roll
dough about 1/2 inch thick. Spread with butter,
cinnamon, and sugar. Roll jellyroll fashion and slice 1/2
to 3/4 inch thick. Place on greased sheets and let rise
'til double. Bake about 15 minutes at 375º. When
almost cool, frost (butter, milk, powdered sugar, vanilla).