Brush around the perimeter of the remaining rectangle of dough with water. Place strips of dough around the edge of the rectangle by using three strips, to prevent the filling from spilling. Spread the filling evenly in the centre of the rectangle up to the dough strips. Brush water around the edge of the dough. Place five strips of dough diagonally, spacing them evenly over the rectangle. Lightly press the strips around the edge. Brush water around the edge. Repeat with the remaining strips in the opposite direction, using the leftovers. Cut the edge of the pastry to remove any excess strips and even up the pastry. Brush the dough with the egg wash and sprinkle with maple sugar, if desired.