01 -
Set your oven to 425°F. If you're using a cast iron pan, put it in now so it heats up.
02 -
Start by mixing the flour, sugar, salt, and baking powder together. Next, cut in or shred the butter. Stir in the sourdough starter, milk, and egg until it becomes a rough dough. Don't knead it. On a floured countertop, fold and mix until the dough just holds together with visible butter bits.
03 -
Flatten the dough to about 6x9 inches, then fold it into thirds. Repeat this three times for layers. Roll it out to a final size of 18x12 inches.
04 -
Combine cinnamon, melted butter, brown sugar, and vanilla, then coat the dough evenly with the mixture. Roll it tightly from one long edge and slice into 12 even pieces.
05 -
Place the slices cut-side-up into a greased 9x13 pan or the hot skillet. Bake for 15-18 minutes until they just start to turn golden.
06 -
Beat the cream cheese until creamy. Add in the icing sugar and mix for a couple minutes. Pour in vanilla and milk, stirring another few minutes. Drizzle over warm rolls right away.