Mix butter and flour with a pastry cutter until incorporated. Use hands to make sure all the butter is mixed in. Add salt and sugar. Set aside.

Warm milk in a glass bowl in the microwave, until just warm to the touch. Sprinkle the yeast over the top and let foam for 5 minutes.

Stir sourdough starter, and eggs into the warm milk mixture and whisk.

Add wet mixture into the dry. Using a silicone spatula, mix until forms a dough. Cover with. moist, but not wet cloth, and let raise for one hour.

Re-wet the towel, and cover and place bowl in refrigerator overnight.

Mix brown sugar and cinnamon in a bowl, making sure to break up any clumps. Sit aside.

Using a mixer, whip butter and cream cheese until fluffy. Add in powder sugar a cup at a time, mixing in between.

Add in vanilla. Add in cream and mix. Set aside until rolls are ready.

Remove dough from refrigerator and place on lightly floured work surface. Roll dough out into a rectangle, about 1/4-1/2 inch thick.

Spread softened butter onto the dough. Leave one long edge with 1/2 inch non buttered.Sprinkle the cinnamon and brown sugar mixture over the butter evenly. Roll the dough up snugly leaving the unbuttered end to seal at the end.

Using a bench scraper or very sharp knife cut dough into equal pieces, and place evenly into a greased baking dish. We sometimes use 2 different dishes, to save one batch to take to a friend!

Cover with a piece of plastic wrap that you have sprayed with cooking spray.  Place in a warm, draft free location to allow rolls to double in size, 1 to 2 hours. If they are fully raised and you are not ready to bake, place in refrigerator.

Pre-heat oven to 400 degrees. Bake for 25 minutes, turning half way through. Pull the rolls out and allow to rest for at least 5 minutes before serving.

Finally, pass the frosting separately to put on while still warm.