1/2 cup cornstarch, 1 cup baking soda, 3/4 cup water, a small saucepan, and a spoon. Heat the mixture over medium heat and stir constantly. Remove from the heat and let the clay cool until you can handle it comfortably. Knead it for a minute to make it really smooth. Shape. Bake at 250F (121C) for 30 minutes...longer if project is thick.
I really loved making these treats and the dogs loved them! I recommend mixing by hand (almost kneading like) once the dough comes together to really get it mixed together well. One batch makes large amount of treats depending on the cookie cutter size.