Thinking...
What if the soul is just a compilation of our individual experiences?
There's no physical thing called a "soul", it isn't a "ghost" inside of our bodies.
Think for a second - when your body is formed inside the womb, you/your soul still has experiences in form of sound, touch, smell, light-sight.
While your "self" is forming, your soul is taking in all of the experiences.
The older you get, the more defined your soul becomes as you have more and more experience.
Even if you were confined to a dark room for your entire life, that in it of itself is still an experience - every small detail, every small thing you ever experience makes you YOU.
This still doesn't explain why i am me and im not you though, you feel me?
So the real question shouldn't be "what is my soul made of?" but rather "What makes me, ME and not you".
Which in turn means, if i copy paste myself, down to the last atom, all configurations all electron placements in time and space, if everything was the same, would i be able to control my clone by thought?
Btw, it helps if you are high while asking yourself the question.