Put all the ingredients but the butter in a mixer with the hook attachment and mix at medium speed for 3 minutes. Add the butter cut in 1 inch cubes and mix at medium speed for 12-13 minutes or until the dough no longer sticks to the wall of the mixer bowl.

Put in a container with lid in the refrigerator for at least 12 hours.
I usually prepare it in the evening to have it ready the morning after. The dough can keep in the refrigerator up to 36 hours.

When ready to shape, take the dough from the fridge and let it rest in the container at room temperature for at least one hour.
Cut into 70 gr pieces (weigh the dough, don’t trust your eyes if you want consistency in the pieces).
Shape as you like. I normally make small balls and roll them on a clean surface to have tight round shapes.

Place on a baking sheet lined with parchment paper leaving enough space between each ball to allow room to grow during raise and cooking.
Cover with plastic film and let rise until doubled in size, preferably at 76-78F. A good option is place the baking sheet in the over off with just the light on.

Pre-heat your over at 350F convection, brush each piece with egg white and bake for 12 minutes. They should have a nice uniform golden color and the internal temperature should be 205F.
Cool over a wire rack.