Dissolve yeast in warm water; let stand 5 minutes.
Combine 1/3 cup sugar, salt, shortening, and buttermilk in a large bowl. Stir in dissolved yeast and eggs. Gradually add flour, stirring until a soft dough is formed. Place in a well greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 2 hours or until doubled in bulk.
Punch dough down. Turn dough out onto a lightly floured surface, and roll into an 18-inch square.
Combine remaining ingredients; spread mixture over square. Roll up jellyroll fashion; moisten edges, and pinch to seal. Cut roll into 1-inch-thick slices. Place slices, cut side down, in layers in a well-greased 10-inch tube pan.
Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in bulk. Bake at 350° for 50 minutes or until golden brown. Cut into wedges to serve.