Step 1: In a medium bowl, whisk together the all-purpose flour, baking soda, cream of tartar, and salt. Set aside.
Step 2: In a large bowl, using an electric mixer, cream together the softened salted butter, 1 1/3 cups granulated sugar, and 1/3 cup brown sugar until light and fluffy, about 2-3 minutes.
Step 3: Beat in the large eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Step 4: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.
Step 5: In a small separate bowl, combine the 1/4 cup granulated sugar and 1 tablespoon ground cinnamon for the coating.
Step 6: Roll the cookie dough into 1.5-inch balls (about 1.5 tablespoons each). Roll each ball generously in the cinnamon-sugar mixture until fully coated.
Step 7: Place the coated cookie dough balls about 2 inches apart on baking sheets lined with parchment paper.
Step 8: Preheat your oven to 375°F (190°C).
Step 9: Bake for 8-10 minutes, or until the edges are set and lightly golden, but the centers still look soft. The cookies will puff up and then flatten slightly with crackled tops.
Step 10: Remove from the oven and let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.