Cut butter into flour until mixture is coarse and granular. Add ice water and mix. Refrigerate overnight. For filling, crumble almond paste; blend in sugar and add eggs and lemon extract. Refrigerate overnight. Divide crust and filling into eight sections. Roll dough into oblong pieces about 14 x 5 inches. Roll each section of filling into a rope and place on rolled out pastry. Bring ends of pastry up to cover filling; then the sides. Brush edges with water to seal and place on greased cookie sheet, seam side down. Brush with egg white and prick at intervals. Bake at 425 degrees for 20 to 25 minutes until golden brown.