Preheat the oven to 350 F. In a large bowl, whisk together the flour, salt, baking powder and cream of tartar.
Using a stand mixer, cream together the sugar, butter and eggs until pale. Slowly add the mixed dry ingredients in quarter cup increments, allowing each addition to completely mix into the wet ingredients before adding the next quarter cup. Repeat until all flour is combined and a sticky dough has formed.
In a small bow, combine the sugar and cinnamon. Working with a tablespoon or measuring spoon, measure out 1-2 tablespoon portions of the cookie dough. Roll the dough into 1 inch round balls.
Roll the dough balls in the cinnamon sugar mixture until completely covered then transfer to a baking sheet lined with parchment or a silicone mat. Place the balls about 1-2 inches apart.
Bake for 8-10 minutes, until the cookies are puffed up in the middle and just starting to brown.
Meanwhile, in a separate bowl (or cleaned mixer bowl) combine the cream cheese, powdered sugar and milk. You may need more milk to make a smooth icing. Only add enough milk so that the icing can be slowly drizzled and is not watery. If too thin, add more powdered sugar.
Transfer the cookies to a cooling rack and allow to cool completely. Drizzle the cream cheese icing over the cookies as desired. Store in an airtight container for up to one week. Enjoy!