Mix the first part of the butter with the first batch of cake flour, roll out, and leave to rest and chill.
Knead the rest of the ingredients together and place in the refrigerator. Make a single fold and a double fold with the butter on the outside.
Leave to rest for 30 minutes in the refrigerator.
Make another single fold and another double fold and again leave to rest in the refrigerator for 30 minutes.
Roll out to 1 mm thick, cut 2 cm x 18 cm strips between two sheets of silicon paper, bake between two metal rings of 7cm in diameter x 2.5 cm in depth (outer ring) and 6.5 cm in diameter x 2.5 cm in depth (inner ring).
Cook at 190º C for 20 minutes, remove, and use as the outer part.