Preheat Oven & Line Tray: Preheat the oven to 356ºF (180ºC) fan-forced and line a baking sheet with parchment paper. Set aside.
Prepare Mixing Equipment: Set up your stand mixer with the paddle attachment, or prepare a large mixing bowl with an electric hand beater.
Cream Butter and Sugar: Add softened butter and powdered sugar to the bowl and beat on medium-high for 1 minute, scraping down the sides as needed.
Incorporate Dry Ingredients: Sift the flour, cornstarch and cinnamon into the bowl with the butter mixture. Beat on low-medium speed until a crumbly dough forms. Use your hands or a spatula to bring the dough together into a soft ball.
Shape and Coat Cookies: In a small bowl, combine granulated sugar and cinnamon for the coating. Scoop 1 tablespoon (25g) of dough per cookie, roll it into a ball, and then roll each ball in the cinnamon-sugar mixture to coat. Place the coated balls on the lined baking sheet, leaving a 2-inch gap between each. Do not flatten the balls.
Bake Cookies: Bake for 12-15 minutes or until the edges are lightly golden and the tops are set. Avoid over-baking for a melt-in-your-mouth texture.
Cool: Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
Notes
Store: Place cookies in an airtight container at room temperature for up to 1 week to keep them fresh.Freeze: These cookies freeze well without losing their texture. Place in a freezer-safe container or bag with parchment paper between layers, then label and freeze for up to 2 months. Thaw at room temperature before serving.