In a large saucepan over medium-high heat, warm the milk, maple syrup (or honey), and butter until melted. Do not boil. Remove from heat and cool until lukewarm. (it CANNOT be hot or it will kill your starter)

Whisk in your active sourdough starter, then whisk in eggs and salt until smooth.

Add 4 cups of flour and mix. (this will be super sticky) Let sit for 2-4 hours or until bubbly.

Mix in 2½–3 cups additional flour until the dough is smooth and workable. Cover and let sit for 30 minutes to an hour. (I make the filling and icing in this time)

Roll dough into a large rectangle on a floured surface. Spread Cinnamon Roll Filling mixture (I do this with the back of a spoon), then roll tightly and slice. Place rolls in a greased baking dish. If cooking same day, let rest in a warm area for 2-3 hours or until double in size. If your cooking it at a later time, cover with a wet towel and let rest for up to 3 days in the fridge. (this is when I put mine in the fridge overnight)

If you had your rolls in the fridge, take them out at this time. Preheat oven to 350°F (175°C).

Once oven is ready, pour heavy whipping cream evenly over the rolls.

Bake for 25 minutes, or until lightly golden on the edges.

In a medium sized bowl, beat icing ingredients until smooth, adding milk as needed. Spread over warm rolls and serve.