Create the Poolish (Flavor Base): In a bowl, combine 6 tbsp lukewarm milk, 2 tsp yeast, and 2/3 cup flour. Cover with cling film and let it rest for 2-3 hours at room temperature or overnight in the refrigerator. Once risen, the mixture should appear bubbly and increased in volume.

Mix and Develop the Main Dough: To the poolish, add 1 cup milk, 3 cups flour, 3.5 tbsp sugar, 2.5 tsp salt, 0.5 tbsp vanilla extract, and 0.5 tbsp softened butter. Mix on medium speed in a stand mixer with a dough hook for 3 minutes. Let it rest for 20 minutes, then continue mixing until the dough is smooth and elastic, about 5-7 minutes. Let it rise for 1-2 hours until it increases by 50%.

Prepare for Lamination: After your dough has risen, flatten it into a rectangle and refrigerate for 4-6 hours to chill.

Beat 22 tbsp cold butter until pliable, shape it into a rectangle, and refrigerate to firm up.

Roll the dough into a 20x10 inch rectangle on a floured surface. Place the butter block on the left two-thirds of the dough, fold the right side over the butter, and seal the edges.

Turn the dough 90 degrees, roll it out again, and fold into thirds. Chill in the fridge for 30 minutes. Repeat this process one more time.

Prepare the Cinnamon-Sugar Filling: Combine 1/2 cup granulated sugar, 1/4 cup brown sugar, 1 tbsp orange zest, 1.5 tsp cinnamon, and 1/4 tsp salt in a bowl and mix well.

Roll the dough into a 16x12 inch rectangle, brush with 3 tbsp melted butter, and sprinkle evenly with the cinnamon-sugar filling.

Roll tightly from the long side and cut into 12 equal pieces. Place the cut buns into a greased baking dish and refrigerate while preheating the oven.

Allow the buns to rise for 1 hour at room temperature.

Preheat the oven to 375°F. Bake for 45-60 minutes or until golden brown. Let them cool for 5 minutes upside down in the pan before transferring to a wire rack.