Heat until shortening is melted; set aside to cool. Dissolve the yeast and 1 teaspoon sugar in the warm water. Beat the eggs, 1/2 cup sugar and salt together. In a large bowl, combine the milk mixture, yeast mixture and egg mixture. Sift the flour and baking powder together, and add to the wet mixture; stir until combined, then cover and refrigerate overnight.
Divide dough into fourths, and roll out on a floured surface.
Spread surface with the soft butter.
Cut dough into triangles, and roll up from larger to small end.
Place rolls on a baking sheet, and allow to rise for 3 to 4 hours. Preheat oven to 400 degrees F (200 degrees C.)
Bake in a preheated oven for 8 to 10 minutes, or until golden brown.
