Autolyse with milk or substitute the milk? I have a sweet dough recipe that calls for milk powder, heavy whipping cream, and whole milk. It also calls for water, but all of it is used in a tangzhong formulation. I would still like to autolyse the remaining flour, but I'm not sure how to do that since I don't have any water left. How can I autolyse?


Combine flour, heavy whipping cream, and whole milk - then let it rest for 20-60 minutes?
Scald the heavy whipping cream and whole milk, combine with flour - then let it rest 20-60 minutes?
Replace the heavy whipping cream and whole milk with UHT milk, combine with flour - then let it rest for 20-60 minutes?
Replace heavy whipping cream and whole milk with powdered milk, then combine the water that should be added to the powdered milk to the flour instead - then let it rest for 20-60 minutes?
Should I add the tangzhong during the autolyze? I'm concerned that there won't be enough hydration unless I do so.


BONUS QUESTIONS:


Generally, what is the hydration level when doing an autolyse?
When a recipe calls for milk powder, is it asking for non-fat milk
powder?
Why would a bread recipe call for heavy whipping cream? Does it have something to do with fat content?
Your sweet bread recipe is similar to a milk bread recipe I have seen recently. An autolyse does require liquid in order to 'start'. It is safe to use a portion of your liquid milk to autolyse the remaining flour as you'd like. 

Milk powder generally is ideal for adding lactic sugars for the maillard reaction. The higher the milk fat content, the greater the maillard reaction will be and therefore your bread will be darker and nuttier in flavour. Heavy cream will have the same affect, and it will create a really pleasant crumb and mouthfeel of the bread because of the high fat content. 

What is your recipe?