Activate yeast by mixing it with warm milk and a teaspoon of sugar; let sit until frothy.
In a bowl, combine flour and salt; add eggs and sourdough starter. Mix well.
Brown the butter in a skillet until golden; add to the mixture along with activated yeast. Stir until shaggy dough forms.
Knead on a floured surface for 5-7 minutes until smooth and elastic.
Let rise in an oiled bowl covered with a towel for about 1 to 1.5 hours until doubled in size.
Roll out dough into a rectangle, spread softened butter, sprinkle with cinnamon and brown sugar, then roll up tightly.
Slice into 1-inch pieces and place in a greased dish; let rise for another 30 minutes.
Preheat oven to 350°F (175°C) and bake for 20-25 minutes or until golden brown.
