Roll the dough to a 12-inch square and place on paper-lined sheet pan. Mark dough into 3 strips, each 4 inches wide and 12 inches long. Slash the two outermost strips diagonally at 1/2-inch intervals, making downward slashes. Spread the filling on the center strip. Fold the slashed pastry over the center strip, alternating a slash from each side. Proof 50 percent. Brush the egg white on the pastry and strew with the sliced almonds. Bake it at 400 degrees about 15 minutes. Cool and drizzle with warm water icing.