Queen cage candy is made by mixing icing sugar (powdered sugar) with warm honey until it is the consistency of putty or plasticene (modelling clay). It is important to know the honey is free from disease before making up such candy, so use your own, not foreign honey that may be infected with foul brood. Bakers fondant can also be used.
There are two basic reasons for using queen candy:-
I gave up using candy as a release agent for queens in 1996 and use marshmallow, which has less tendency to go too hard for the bees to nibble it. If the bees do ignore it, then it shrinks and falls out of its own accord. Even the use of marshmallow has now been replaced by the Albert Knight/Steve Taber/John Dews Method, which I find totally reliable.