Mix all of the ingredients together, and stir over low heat. The dough will begin to thicken until it resembles mashed potatoes.
When the dough pulls away from the sides and clumps in the center, as shown below, remove the pan from heat and allow the dough to cool enough to handle.
IMPORTANT NOTE: if your playdough is still sticky, you simply need to cook it longer!
Keep stirring and cooking until the dough is dry and feels like playdough.
I've gotten many comments asking about sticky dough, so please just keep cooking a bit longer and it will work!