Pre-heat oven to 415 degrees then line the baking sheet with parchment paper.
In a medium bowl, sift together the flour, baking powder, sugar, cream of tartar and salt.
Using a pastry blender, your hands or a knife and fork, cut the butter until the flour resembles coarse crumbs.
Add the milk and stir with a fork until the mixture comes together. On a lightly floured surface, remove the dough and knead until smooth.
Roll out dough to a thickness of ½ inch. Cut the dough with a 3-inch butter cookie, or you can cut it into squares. With the rest of the dough, shape and roll out to ½ inch and repeat until all the dough is used and made into cookies.
Arrange cookie dough on prepared baking sheet and bake for 10 to 12 minutes, or until raised and golden brown.
Serve immediately or place on a counter or serving platter until ready to serve.