Make the Tangzhong roux: Whisk 25g bread flour and ½ cup water until smooth. Cook on medium-low heat, stirring constantly, until thickened to the consistency of pudding. Remove from heat and let cool.

In a large bowl, combine 475g bread flour, 1 tbsp white sugar, 1.5 tsp salt, and ¼ cup grapeseed oil.

Add 2 Tbs starter to the cooled Tangzhong roux. Add ¾ cup room temperature water to the roux mixture and give it a quick mix.

Add the roux mixture to the flour mixture and mix until no dry flour is left.

Let the dough rest for 30 to 60 minutes.

Gently knead the dough until it is smoother and more elastic.

Throughout the day, perform gentle folds every 2 to 3 hours, about 3 to 4 rounds.

Lightly grease a baking pan with butter.

Make the cinnamon filling: Combine 4 Tbs softened salted butter, ⅓ cup dark brown sugar, and 1 Tbs cinnamon. Mix until spreadable.

Lightly flour a surface and roll out the dough as large as possible.

Spread the cinnamon filling evenly over the dough, leaving about 1 cm of dough without filling on one edge.

Roll the dough tightly from the short edge to create more layers.

Pinch the free edge to seal the roll and gently wiggle to stretch it out.

Cut the roll into nine pieces.

Place the rolls in the prepared baking pan.

Let the rolls proof overnight at room temperature (or in the fridge if your home is warmer).

About 20 minutes before baking, let the rolls sit out at room temperature.

Just before baking, brush the tops of the rolls with 2 Tbs of melted butter.

Bake at 325°F for 35-40 minutes, until the tops are lightly browned.

While the rolls are baking, make the cream cheese icing: Soften 4 Tbs salted butter and 4 oz cream cheese. Add 2 tsp vanilla paste or extract and mix. Gradually add 1 cup powdered sugar, mixing until smooth and to your preferred sweetness.

Once the rolls are out of the oven, apply the cream cheese icing while they are still warm.