01 -
Heat your oven to 350°F and line baking sheets with parchment paper for easy removal.
02 -
Beat the softened butter and sugar together in a large bowl for 4-5 minutes until the mixture becomes light and airy. Scrape down the bowl sides, then add eggs and vanilla, beating for another 1-2 minutes until well combined.
03 -
Gently fold in the flour, cream of tartar, baking soda, and salt, mixing just until everything comes together - don't overmix.
04 -
Whisk together the sugar and cinnamon in a small bowl until evenly combined.
05 -
If you have time, chill the dough for 20-30 minutes for easier handling. Roll portions into smooth, walnut-sized balls, then roll each ball in the cinnamon-sugar mixture twice to ensure complete coverage. For flatter cookies, gently press down the center of each ball before baking.
06 -
Arrange coated dough balls on prepared baking sheets and bake for 9-11 minutes. The cookies should look slightly underdone when you remove them - they'll finish cooking on the hot pan. Let them rest on the baking sheet for a few minutes before transferring to a cooling rack.