Not sure who told you that a COT isn't an "official proof of ownership", it is 100% legal and valid form of official ownership of a property enforced by law.

Now I'm guessing you are talking about selling the property to a traditional buyer, or trying to get title insurance using a poorly trained title company who might not know this because it lacks the "warranties" of a standard Warranty Deed. Some title companies or buyers might be hesitant until certain steps are taken.

If you want a different form of "deed", it's super simple to more complex.

Easiest thing to do is to quit claim the property to yourself or a business entity. You can easily create your own quit claim deed document using online templates, and E-file it with the county after having it notarized for roughly $50.
If you want a warranty deed, you would need to first do a quiet title action, which you can do yourself if you are up to the legwork, or use an attorney which will cost $1500 to $3500 depending on the complexity of the property's title. After this you can get title insurance.