Can you sell a condo unit in NYS without condo declaration being recorded?

No. The recording of the declaration of condominium creates the condominium under state laws. A condominium is a creation of law. If no condominium is created then no units can be sold.

Condominium declarations are recorded in the land records office where the land is located. Once the condominium has been submitted to the provisions of state condominium law by the recording of the declaration in the land records, the developer can sell condominium units.