In a mixing bowl, combine the yeast and flour; add butter and mix well. Add egg yolks and sour cream; mix well. Shape into four balls. Place in re-sealable plastic bags; refrigerate overnight.
2In a small bowl combine sugar, pecans and cinnamon; set aside.
3On a floured surface, roll each ball of dough into a 9-in. circle. using a pizza cutter, cut each circle into 16 wedges.
4Sprinkle with sugar mixture and apple; roll each wedge up from the wide edge and pinch to seal.
5Place with point-side down on greased baking sheets. Bake at 350 degrees for 16-20 minutes or until lightly browned. Immediately remove to wire racks to cool.