Combine milk and flour in a small sauce pan and heat over medium until it becomes a thick paste. Whisk constantly so it doesn't stick and burn. Cover and set aside to cool.
Dough
In the bowl of a stand mixer combine milk, eggs, yeast, and sugar.
In a separate bowl weigh out flour and salt and whisk to combine.
Add the dry ingredients and tangzhong into the wet ingredients and set stand mixer to medium speed and mix until combined.
Add in softened butter and let stand mixer knead for another 10-15 minutes until the dough is soft and smooth.
Form dough into a ball and set in a greased bowl. Cover and let rise until doubled in size. About an hour (use more time if you need, go based off the size of the dough rather than the clock).
Assembly
When the dough is about doubled in size, combine softened or melted butter with sugar, cinnamon, and salt and mix until it's a paste.
Punch down the dough and turn it out onto a lightly floured surface. Roll the dough out to 12x24. Spread the paste onto the dough evenly and roll up into a log. The log should be 24 inches, if it's not, use your hands to gently stretch the log until it reaches around 24 inches.
Using a sharp serrated knife cut every 2 inches and you should get 12 even rolls.
Set them in a baking dish and cover for 30 minutes.
Baking
Preheat the oven to 350℉. When ready to bake, uncover rolls and pour heavy cream over each roll.
Bake for 25-30 minutes until bubbly and golden brown.
Frost with cream cheese icing when no longer very hot. They can still be warm but the frosting will melt slightly.
Cream Cheese Frosting
Cream butter and cream cheese together for a minute to combine. Add Powdered sugar, salt, and vanilla and whip for a few minutes until it's fluffy.