Mix molasses, baking soda and cream of tartar together in a large glass measuring cup and set aside. Mixture will get frothy. In a large mixing bowl, cream sugar, shortening and eggs together. Slowly mix in molasses mixture, then milk, and then dry ingredients. Dough is soft so the entire recipe can be put together with a good stand mixer.
Drop by rounded teaspoonful on greased and floured cookie sheet.
Bake at 400 degrees F for 8 - 10 min. Do not overbake as they burn quickly. Cookie should be set and is slightly cake-like.