Trying to make a chocolate initial ( letter) to stand up on top of cupcake.
I made some and put on wax paper, froze them but after they got room temp they were too soft to stay up. I'm just melting chocolate, doew something else have to be added?

I would try using royal icing. It hardens really well, and can be brittle if you allow it, but will not melt.

If you do a run out, you can make a large enough, and super cute one. Start by printing out a very large letter (size you're looking for), place wax paper over it and trace. Then use soft peak royal icing to outline your letter on the wax paper. After that has hardend for a little while, add water to your remaining icing to make it runny. Flood your outline with it (same color or different color) and let it harden for at least a day or two.

HTH