Activate yeast in the warm water in a measuring cup that has room for the expansion of the yeast. Make sure it is active and bubbly.
In a large bowl, combine 4 cups of the flour, 1/2 cup sugar, and salt. Add yeast and shortening. Lightly beat eggs and add them with the last cup of flour. Mix thoroughly. Spray with non-stick cooking spray and cover bowl with plastic wrap. Let rise in a warm place until doubled in bulk.
Melt 1 cup of butter for filling.
Combine sugar, butter, and orange rind.
Melt the other 1/2 cup butter.
You will need a 15" x 20" work surface. Punch down dough and cut in into 4 evenly sized portions. Sift 1/4 cup flour evenly over work surface and roll 1/4 of the dough into a 15" x 20" rectangle. Spread a fourth of the filling over the dough and form into a jelly roll starting with the 20" side. Repeat this procedure for the remaining 3 portions of dough.
Cut each roll of dough into 16 slices. Place one slice in middle of greased pan, surround with 5 slices and surround those with the remaining 10 slices. Brush with the melted butter, cover loosely with plastic wrap and let rise, when the rolls are almost touching the plastic wrap, remove and allow to continue to rise until doubled in bulk.
Bake rolls in a 375°F oven until lightly browned (15-18 minutes).
Combine powdered sugar, orange juice, and orange rind and drizzle over slightly cooled rolls.