Does this have to be cooled in one mass and cut into squares?

I imagine you could drop it in mounds with a spoon, but I don't think you'd have any luck piping it. The mixture would be too soft to hold any kind of shaping from a tube, and would likely be too warm to comfortably handle in the piping bag. Soft nougat is not really a shapeable sort of thing. However, you could drop it into a silicone mold that had individual shapes, and let it cool in those.