We like to put our logo on the pieces we create using our signature stamps. Sometimes it is difficult to add it during the "building" process without damaging the front of the piece before baking or sometimes I would simply forget so I have found a way to add it later.
I do this by first running some clay through a very thin setting on the pasta machine. You want it thin enough so it doesn't stand out much on your piece but not too thin or it will tear when it is stamped.
You may need to use a mold release of some sort such as lightly dusting the clay sheet with some cornstarch or spritzing with water. Make an impression in the clay with your stamp. I sometimes do several at a time or you may have to do a few for practice until you get one with an even impression that you like.
Cut out around your stamp using a shape cutter.
Add a little bit of liquid clay to the back and position it onto the reverse side of your piece and rebake.