Preheat oven to 325.
Beat the melted butter until soft.
Fold in sugar slowly.
Fold in the flour.
Add cornstarch and salt and vanilla
Move the dough to cutting board dusted in flour.
Divide the kneaded balls of dough into 4 or 5 sections and place in your fridge for one hour maximum. (We initially left ours too long. Don't do that.)
Making sure that your cutting board is constantly coated in flour you can roll the dough balls out individually (kids do this very well) and begin to cut into shapes. Re - coat the cutting board periodically with flour and place on your hands as well to keep dough from sticking.
Careful not to over flour the dough or the shortbread will be dry.
Place the cut cookie shapes onto a cookie sheet and bake for 15 minutes.
You can line the sheet with parchment paper and they won't stick.
Let each batch cool a bit and enjoy. You can decorate these or make them fancier, but the taste here is so good they don't really need anything more.