1. Dissolve yeast in warm water in a large bowl. Let stand until bubbles/ foams with a pinch of sugar (8-10 minutes).
2. Add white sugar and salt.
3. Add ½ cup flour and the egg, then stir well.
4. Add remaining flour gradually as you stir, forming an elastic dough.
5. Put on floured surface and knead for 5-10 minutes until the dough becomes smooth and easily forms a large ball.
6. Cover with a cloth and leave for 10 minutes.
7. While dough rests, grease a 9” round pie dish.
8. With a rolling pin, roll out dough on the floured surface into a long oval or rectangle shape, about 10” in length and ¼ in thick.
9. Spread butter over entire surface of dough.
10. Sprinkle brown sugar and cinnamon evenly on the surface.
11. Using a pizza cutter, cut dough into six, 1 ½ inch wide strips.
12. Loosely roll up one strip at a time, starting in the center of the pie dish, with cinnamon and sugar side in. Continue to roll each strip around the previous in a spiral pattern.
13. Cover the dish with plastic wrap and refrigerate overnight.
14. In the morning, get out of the fridge and let sit at room temp for 1 hour.
15. Bake at 325 degrees for 30 minutes uncovered, turn in oven for even browning and cook uncovered 10 min longer. Then cover with foil and cook 10 more minutes covered or until center is set and not gummy.

For the frosting:

1. Sift powdered sugar through a sieve or whisk clumps out in a medium mixing bowl.
2. Add milk gradually, adding a bit more to achieve desired consistency.
3. Add vanilla and stir to combine.
4. Drizzle on top of warm cinnamon roll, slice and serve!