The night before you make the dough, take 25 grams of sourdough starter out of the fridge. Add 100 grams of water and 100 grams of bread flour to the jar of starter. Mix everything together thoroughly until there aren’t any dry bits of flour left.

Mark the top of the starter with a rubber band, cover it up loosely, and let the starter rise overnight for around 8-12 hours. The starter should have doubled in size and be ready to use the next day.

To a mixing bowl, add the milk, sourdough starter, softened butter, brown sugar, egg, and salt. Stir together gently to combine. Then, add the bread flour and mix thoroughly to form a cohesive dough.

Transfer the dough onto an un-floured surface and knead by hand for 8-10 minutes until the dough forms a smooth ball. Alternatively, you can mix the dough in a stand mixer for 8-10 minutes. Start mixing at low speed for 1-2 minutes and then continue mixing on medium-low speed for 6-8 minutes until the dough is finished kneading.

Knead the dough a few times by hand to form a smooth ball of dough to prepare for the first rise.

Place the dough back into the mixing bowl, cover it up with a kitchen towel, and let the dough rise at room temperature for about 4-8 hours. The dough should double in size again during this time.

Once the dough has risen, move it to the fridge to chill for 15-30 minutes while you make the cinnamon-sugar paste for the filling.

To make the cinnamon-sugar paste, add the softened butter, brown sugar, and ground cinnamon to a mixing bowl. Whisk together the ingredients with a fork until it forms a light and fluffy paste.

If the butter is too firm and the mixture becomes crumbly, heat up the paste in the microwave for 5 seconds and then try to whisk it again. 5-10 seconds in the microwave should melt the butter enough to make it whisk easily. Whisk thoroughly to form a spreadable paste.

Take the dough out of the fridge, dust each side of the dough lightly with flour, and press it out on the counter to form a rough rectangle.

Roll out the dough with a rolling pin to form a thin rectangle that measures roughly 18″x12″.

Add the cinnamon-sugar paste to the dough in six dollops and spread it all over the dough. Cover the dough from end to end in the paste, leaving only a one inch gap of dough along the long end free of paste. This empty stretch of dough will help the dough seal and stick together when you roll up the cinnamon rolls.

Starting on the long end of dough with the paste spread to the edge, roll the dough into a tight cylinder. Try to keep the thickness of the roll as even as possible from end to end.

To divide the roll into 9 large cinnamon rolls, slice the dough gently into three equal portions with a serrated knife, then slice each of those three portions into three smaller portions. This will give you nine rolls that are all close to 2″ in height.

Arrange the sliced sourdough cinnamon rolls, spiral-side-up, into a buttered 9×9″ square cake pan.

Cover up the rolls with plastic wrap and allow them to proof. You have three proofing options: Option 1: Let the rolls rise for 2-3 hours at room temperature before baking. Option 2: Let the rolls rise for 2 hours at room temperature and then move them to the fridge until whenever you want to bake them the following day. Option 3: Move the shaped rolls straight to the fridge and let them proof in the cold environment for at least 8 hours but up to 48 hours

.30 minutes before the rolls are done proofing, preheat your oven to 350ºF (180ºC) and let it preheat for half an hour.

Once the easy sourdough cinnamon rolls have proofed, it’s time to bake the rolls and prepare the powdered sugar glaze.

Bake the sourdough cinnamon rolls on the middle rack of the oven for 35 minutes at 350ºF (180ºC). You don’t need to add any steam to the oven while baking.

While the rolls bake, prepare the powdered sugar glaze by whisking together the milk and powdered sugar. Add a little more milk to thin out the glaze, or add a little more powdered sugar to make it thicker. Once you’ve got a consistency that you’re happy with, whisk in the vanilla extract and set the glaze aside.

When the rolls come out of the oven, add the glaze in two stages. Pour half of the glaze onto the easy sourdough cinnamon rolls when they are fresh out of the oven. Then, let the rolls cool for 30 minutes. The warm rolls will soak up some of the glaze and the glaze will form a hardened shell as the rolls cool down. After 30 minutes, add the rest of the glaze and spread it out over the top of the rolls. Since the rolls are not piping hot anymore, the second layer of glaze will sit on top of the rolls without melting and pooling in the edges of the pan.

Serve these easy sourdough cinnamon rolls directly from the baking cake pan, or carefully transfer them to another serving dish.