01 - Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, cornstarch, baking soda, cream of tartar, and salt.
03 - In a large bowl, beat the softened butter and granulated sugar until the mixture is light and fluffy, approximately 2-3 minutes. Incorporate the egg and vanilla extract, beating until well combined.
04 - Gradually add the dry ingredients to the wet mixture, stirring just until fully integrated.
05 - In a small bowl, combine the granulated sugar and ground cinnamon.
06 - Scoop tablespoon-sized portions of the cookie dough and roll them into uniform balls. Subsequently, roll each ball in the prepared cinnamon sugar mixture until evenly coated.
07 - Arrange the coated cookie balls on the prepared baking sheets, ensuring they are spaced 2 inches apart. Bake for 9-11 minutes, or until the edges appear set and the tops are slightly underbaked, maintaining a soft and pale appearance.
08 - Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.
09 - For the frosting, beat the softened cream cheese and butter together until smooth. Gradually incorporate the sifted powdered sugar, vanilla extract, and a pinch of salt, beating until the frosting is fluffy and well combined.
10 - Once the cookies have fully cooled, spread or pipe the cream cheese frosting onto each cookie. Optionally, dust with additional cinnamon sugar for extra flavor and visual appeal.