In a bowl combine flour, salt, baking soda, and cream of tartar. Whisk together and set aside.
In another bowl, with an electric mixer combine butter, oil, and sugars. Cream together. Add the egg, and water, mixing well, then slowly add the dry ingredients and mix just until combined.
Form dough into golf ball-sized dough balls, and lay on a greased cookie sheet. With a small glass cup, dip the bottom of the cup in the reserved 1/4 cup sugar, then use it to smash the dough down flat and give you that Swig-esque rim. Bake at 350° F for 8-10 minutes. Do not overcook!!! Set aside to cool, then top with frosting (recipe below), toasted coconut, and Cadbury mini eggs- the *best* part!