1. Mix yeast w/warm milk & pinch of sugar, stir and let sit for 5 min. to activate
2. Combine egg, sour cream, vanilla and butter, whisking thoroughly, then stir in yeast mixture
3. In separate bowl, combine 2 (3) cups of flour, sugar and salt, stir in yeast mixture
4. Stir in remaining flour until your dough forms a ball and can be removed from the bowl, to the counter for kneading
5. Knead dough, adding just enough flour to make it smooth and elastic, approximately 7-8 min.
6. Spray or oil your bowl for rising, place dough in bowl, then flip it over (so that it is greased on both sides) Cover and place in warm oven or area to raise till double in size, approximately 40 min
7. Remove from bowl to floured surface, punch down to remove air pockets, shape into loaf and place in prepared pan.
8. Cover and place in warm oven to raise until double, about 35 - 40 min
9. Preheat oven to 350, bake for 20 - 22 min
10. Remove from oven and remove from pan to wire cooling rack immediately.