The Night Before (around 7pm): In the bowl of a stand mixer fitted with the hook attachment, combine the flour, sugar, yeast, and salt. Mix well.
On LOW speed, gradually add in the cool water, then the softened butter. Knead until a soft and pliable dough that pulls away from the stand mixer bowl, about 5-6 minutes. In the dough seems too sticky, add up to 3-4 tablespoons more flour.
Cover with plastic wrap to rise 30 minutes. Transfer out to the counter, press into a ½” rectangle, wrap tightly with plastic wrap, then place on a large platter or baking dish to chill in the fridge 4 hours to overnight.
The Next Morning (around 7am): Using a large piece of parchment paper, fold it so you have an 8×10” rectangle. Slice the butter sticks into thirds and evenly divide amongst the center, fold in the parchment flaps to seal in the butter, then roll out so you have an even 8×10” butter slap. Place in the fridge for 10 minutes while you roll out the chilled dough. TIP: You want the butter to stay malleable, so it will bend without breaking.
Set out the butter for the filling to become very softened.
For the First Rolling: Roll out the chilled dough on a very floured surface to a 16×10” rectangle. Place the butter slap in the center of the dough so both 10” sides align with each other. Fold in each flap to meet at the center and pinch all sides to seal in the butter, then flip over so the seal-side faces down.
Using a rolling pin, gently pound the dough vertically then rotate to pound horizontally. Once pounded, begin the evenly roll out the dough vertically then horizontally. Alternating sides will help the butter to evenly spread without breaking up.
Trim the ends with a sharp knife or pizza roller. Fold one third of the dough into the center, then fold the remaining side on top. Cover and chill in the fridge 30 minutes.