Combine flour, salt, cocoa, cream of tartar and coconut oil in a large saucepan over medium heat. Add hot cocoa and vanilla extract.

Continue cooking, stirring constantly, until mixture begins to solidify and pull away from sides of the pan, about 5 minutes.

Remove from heat and flip the dough out onto a floured surface, allow to cool enough to touch then knead for 2 minutes until smooth.

Once the dough is completely cooled it is ready for play.