In a large bowl, cut cold butter into flour until the mixture has a crumb-like texture. Make a well in the centre, add cold water. Mix together until the mixture forms a ball. Do not overmix. Chill dough.
Preheat oven to 220 degrees C. Grease baking trays.
In a medium bowl, blend together almond paste, eggs, 3/4 cup sugar, almond essence and salt.
Divide dough in 4 parts and roll into 35cm strips. Place filling along the centre of each long strip of dough. Roll up and pinch the ends to seal. Place strips 5cm apart on baking tray. Brush with egg white and sprinkle with the remaining sugar.