Mix starter, flour, butter, sour cream/yogurt, eggs, salt & vanilla until smooth.
Cover & rest 6–24 hrs at room temp.
Heat oven to 375°F.
Mix cinnamon + sugar.
Roll dough to 15×18", spread cinnamon sugar.
Fold in thirds like a letter → rotate → roll to ¼" thick.
Cut into 1" strips, twist & place on lined trays.
Bake 15 min, cool slightly, enjoy!