1. Proof yeast with warm water until bubbles form.
2. Mix yogurt, butter, eggs, salt and vanilla together.
3. Add 6 cups flour and yeast to mixture in alternating quantities.
4. Remove dough from mixer and knead for three minutes. Shape into 2 balls of equal size, adding flour until dough is just sticky. Refrigerate for at least 2 hours. (will keep up to 4 days)
5. Roll out to 1/4 inch square, and brush with melted butter. Sprinkle with cinnamon-sugar mixture, and cover with more melted butter.
6. Roll into a log and cut into 10 rolls.
7. Bake at 350º for 20-30 minutes, in a greased 9x13 pan, rotating 1/2 way through.
8. Combine powdered sugar and milk until runny, top rolls with glaze.