Steps

1. In a medium bowl, stir together the flour, cream of tartar, baking soda, and salt. Set aside.
2. In a large mixing bowl, beat the butter with an electric mixer on medium to high speed for 30 seconds. Add the 1½ cups sugar. Beat until combined, scraping the sides of the bowl occasionally. Beat in the eggs and vanilla until combined.
3. Beat in as much of the flour mixture as you can with the mixer. Using a sturdy rubber scraper or wooden spoon, stir in any remaining flour mixture. Cover and chill the dough for about 1 hour, or until easy to handle.
4. Preheat the oven to 375 degrees.
5. In a small bowl, stir together the ¼ cup sugar and the cinnamon. Shape the dough into 1½-inch balls. Roll the balls in the sugar-cinnamon mixture. Place the balls 2 inches apart on an ungreased cookie sheet.
6. Bake in the preheated oven for 10 to 12 minutes, or until the edges of the cookies are golden brown. Transfer to a wire rack and let cool.