• In a mixing bowl, combine 1 stick cold butter (grated using a cheese grater), sourdough starter discard, buttermilk, sugar, and salt. Blend the ingredients using a spatula until they are well incorporated.
• Add the flour and using your hands or a dough hook with a stand mixer, kneed the mixture into a stick but smooth dough ball.
• Add the dough to a greased bowl and let it rest on the counter overnight (10-12 hours).

Morning Prep Steps

• Preheat the oven to 375°F (190°C) and grease a deep 11x16 baking dish.
• Create the leavening agent mixture by combining the baking powder and baking soda in a small bowl using a fork until the mixture is free of lumps. Spring the dough with the mixture and kneed it in before rolling out the dough.
• Roll the dough out on a floured workspace and rolling pin, creating a 12" x 24" rectangle.
• Mix the remaining softened butter with the brown sugar and cinnamon, then spread it across the dough.
• Roll the dough into a log and slice it into 12 pieces, placing each piece in the baking dish with some space for expansion. Let it rest for 1 hour.
• Bake for 35-40 minutes in the preheated oven until the tops are golden brown.
• As the cinnamon rolls bake, mix the ingredients for the frosting. Apply the glaze to the hot rolls once baked.
• Let cool and then enjoy!