I just used regular Titebond III.
I cut the name in maple and they glued that piece to another piece of maple. Then cut the oval that way you don't have to worry about mistakes between the top and bottom.
I can't remember any issued with the glue when heating of the clay.
Only did a few and no one complained afterwards.
These were made some 6 years ago and I know that one is still on her backpack.