For the dough: In a small saucepan, combine the butter and milk. Heat until warmed and the butter has melted. Set aside until needed.
In the bowl of a mixer fitted with the dough hook attachment combine the eggs, vanilla extract, active starter and honey. Mix to combine. Slowly add in the warm milk and butter mixture.
Add in the flour and salt. Mix fully then start kneading the dough. Knead on the lowest setting for 8-10 minutes or until you have a soft and elastic dough. At this point the dough should be slightly sticky.
Cover with a damp towel and let rest for about 40 minutes. After 40 minutes stretch and fold the dough by grabbing one side of the dough, stretching it out as far as it will go without tearing, fold it over the top of the dough, turn then repeat until you have stretched and folded 4 times. Cover and let rest for 15 minutes. Repeat the stretching and folding process again.
Once the stretching and folding has been completed the second time, lightly cover the dough with oil, place the damp towel back on and let the dough bulk ferment overnight.
In the morning: Remove the dough from the bowl and place on a lightly oiled work surface. Roll the dough out into a 12" x 16" rectangle.
For the filling: Combine the softened butter, brown sugar and cinnamon. Spread in an even layer on the dough, leaving an ½" space around the edges.
Starting with the long end roll the dough up into a long log. Try to keep it tight as you are rolling it up.
Cut into equal pieces. For larger rolls cut into 1" pieces. For smaller rolls cut into 1 ¼" to 1 ½" pieces.
Place in a well-greased or lined 12" cast iron pan or any other baking dish lined with parchment paper. Cover with a towel and let proof until puffy, approximately 1 to 2 hours.
When the dough is almost done proofing, preheat the oven to 350°F.
When the rolls are fully proofed place in the oven and bake for 30 minutes. Remove from the oven and allow to cool for 5-10 minutes before adding the icing.
For the icing: Combine the powdered sugar, heavy cream and vanilla extract in a small bowl. Once the cinnamon rolls have cooled slightly spread the icing all over the rolls. Enjoy!