Posted this to Cake Decorating forum but have gotten no response:

I'm making a Darth Vader cake and have a shaped pan to make everything easier. This will be sitting on top of a 14" round. I was originally going to have the smaller vader cake on top of the round, but then I got the idea to make a candy plaque using the pan, which I did today. I was just going to make the plaque for his facial mask and still bake the cake to make his helmet and all fuller, setting the plaque over the face area. Now I'm not so sure.

I did the plaque rather shallow, so it's not as deep as it would be if I'd made a cake, so his entire helmet isn't included. I could redo the plaque and fill chocolate all the way to the rims of the pan, but would that make the plaque too heavy?

Sorry, I'm having a hard time visualizing what you're trying to do from the description you gave. You have a Darth Vader pan and want to make a piece to stand on top from chocolate, molded from teh pan?

If you let the chocolate start to set to form a thick shell then turn the tin over to finish setting the still runny chocolate would empty out and could be reused and the mask/head will not be so heavy. Or you could line the tin with a thiner layer of chocolate either by pouring or painting and then fill with refrigerator cake or truffle or rkt whatever you think the eaters would like. Once the whole thing is set decant it and the chocolate will give a nice finish hopefully. I haven't done this for a long time and then I used a fish shaped jelly mold, I like marzipan so I lined the mold with chocolate then a thin layer of marzipan then filled with truffle, because the truffle was going to stay soft I sealed the back with marzipan and chocolate so it would keep it's shape.
HTH

Yours aye

Puss