Make the dough in the evening and let it rise overnight in a warm kitchen.
Combine the frozen grated butter and flour in a stand mixer. *NOTE: The frozen butter will make your dough more flakey.
Add in buttermilk, starter, sugar, salt. Mix for 2-3 mins with a dough hook.
Cover the kitchen aid mixer bowl with plastic and leave it out on the counter overnight or on top of your fridge for the bulk rise.
I like to prepare my cinnamon sugar filling the night before.
Cinnamon sugar filling – Combine brown sugar and cinnamon. Mix well, cover, and leave for the morning.
In the morning - Lightly flour your counter top to prevent sticking. Take the dough out onto the counter and cut into 4 equal size balls of dough. Gently stretch it out and roll with a rolling pin into a circle about 10 inch diameter. The dough should be soft and pliable.
Using a pastry brush, brush melted butter on the bottom layer of dough, then add 1/3 of the cinnamon sugar mixture.
Then add one more circle of dough on top and repeat the butter and cinnamon sugar.
Repeat the butter and cinnamon sugar on the 3rd dough circle and then cover with the 4th layer of dough.
Cut the dough like a pizza but not all the way to the middle. You can place a bowl in the middle to make sure you don't cut there.
Place on a parchment paper. Let it rise for the second time for about 2 hours.
Preheat your oven to 350 F.
Bake for 30-40 mins on a large cookie sheet. You will know when it's done by the golden color.
Glaze – While the sourdough star is baking, prepare the glaze by combining the powdered sugar, butter, heavy cream, and vanilla powered. On low heat melt everything together into a glaze.
Once the star is baked, glaze, and serve. It taste just as good completly cooled or even the next morning for breakfast.
Your family will love you!