In a large bowl combine the melted butter, milk, egg, sourdough starter, and sugar. Mix to combine. Add the flour and salt. Mix to combine, the dough will be sticky. Cover with a damp towel and let rest for 30 minutes.

After the dough has rested, knead for 5-10 minutes. The dough should feel soft and smooth. Add flour as needed during the kneading but try not to add too much.

Transfer dough back into the large bowl. Cover with plastic wrap. Let rise overnight until double in size, about 8-10 hrs. (@70 F, this time will depend on temperature).

In the morning: Line a cast-iron skillet or baking dish with parchment paper.

Lightly flour your countertop to prevent sticking. Pour the dough out of the bowl. Gently pat into a rough rectangle.

Roll the dough into a 18 x 12-ish rectangle. If the dough resists, let rest for 5-10 minutes and try again.

Spread the softened butter from the filling ingredients onto the dough. Then sprinkle with brown sugar and cinnamon.

Starting on the long side of the dough, roll it into a log pressing down gently as you go. Take your time with this step. The log needs to be tight so the swirls stay in tact. TIP: if the dough starts to get sticky from the heat of your hands, lightly oil or flour your fingertips, take a deep breath and try again. I also will occasionally use a bench scraper to help me pull the dough away from the counter if it is too sticky.

Cut the dough into 2-inch sections using a oiled knife or bench scraper.

Place the rolls into the lined pan and let rest for about 2 hours, or until the dough puffs up. Alternatively, if you’d like to chill or freeze the rolls, do that at this step.

Preheat oven to 350 F. Bake the dough onto the center rack and bake for 35-40 minutes. The tops should turn light golden brown when ready.

Remove from the oven and cool in the pan for 15 minutes. This helps the butter to absorb back into the dough. Then lift up the rolls, while still on the parchment paper, and transfer to a wire rack.

While the rolls are baking or cooling make the glaze. In a bowl combine butter, cream cheese, vanilla extract and powdered sugar. Beat until smooth, thinning out the consistency with milk as needed.

To serve, top the rolls with some of the glaze or lightly dust with powdered sugar.