In a small bowl, combine 2/3 cup sugar, shortening, salt and 1 cup boiling water; set aside.
In a large bowl, dissolve yeast in 1/2 cup warm water. Add eggs and the water/sugar mixture; beat well. Beat in 2 cups flour. Stir in the remaining flour, 1/2 cup at a time, beating well after each addition. Mix until a stiff dough has formed. Cover with a damp towel and let rise until doubled, about 45 minutes.
Preheat oven to 375 degrees F (190 degrees C). Lightly grease three 8x8 inch baking pans.
In a small bowl, combine 1 cup sugar and 1 tablespoon cinnamon. Roll dough into small balls. Dip balls in melted butter, then roll in cinnamon sugar. Roll balls into 4 inch long cylinders and tie into knots. Place knots into prepared pans.
Bake in preheated oven for 15 minutes, until golden. Serve warm.
