I purchased some silicone molds online to make custom decorated birthday cakes for my son. When I tried to make cake in these molds I had a problem with the cakes sticking. I buttered and flour coated the molds and still stuck. 

Can someone tell me what to do that will keep these from sticking.

 Should I use bakers secret spray? How is the spray as far as ingredients? This stuff any good or not so good?