Prepare the Yeast: Before you're ready to work with the dough, prepare the yeast. In a small bowl, add 1 1/2 tsp of water to the yeast, and mix until it forms a paste.
Incorporate the Yeast: Remove the dough from the fridge. It will be firmer and more developed. Press and stretch it gently into a rough rectangle.
Spread and Knead: Smear the yeast paste across the surface of the dough. Begin kneading by hand for about 3 minutes until the yeast is fully incorporated.
Add the Butter: Once the yeast is fully mixed in, add the softened butter to the dough. Continue to knead for another 5 minutes. At first, the dough will become slippery and may fall apart, but keep kneading until the butter is fully absorbed and the dough becomes smooth, supple, and slightly tacky but not sticky.
First Proof: Form the dough into a ball, and cover the bowl with a cloth or plastic wrap. Let it rise in room temperature for about 1 hour, or until doubled in size.