This is Pluffy Clay that is a Polymer clay made by Polyform who makes Sculpey. It's the clay I use in most of my molds. Wonderful for the Peeps and cookies and more! 
It is a polymer clay so it does need to be baked at 225-225 F for 15 minutes to cure.

You can mix clay softener into it if you need to. 

This brick is the same size as the 2 once Sculpey bricks.