How to Make It
Heat oven to 350° F. With an electric mixer, beat the butter, brown sugar, and ¼ cup of the granulated sugar on medium-high speed until creamy, 2 to 3 minutes. Add the vanilla, salt, and ¼ teaspoon of the cinnamon and beat until combined. Reduce the mixer speed to low and gradually add the flour, mixing just until combined (do not overmix).
On a small plate, stir together the remaining 2 tablespoons granulated sugar and ¼ teaspoon cinnamon.
Shape the dough into balls (about 1 teaspoon each). A few at a time, roll the cookies in the cinnamon sugar to coat and place on baking sheets, spacing them 1 inch apart. Bake, rotating the baking sheets halfway through, until puffed and golden, 10 to 12 minutes. (Cookies will deflate somewhat.) Cool slightly in the pans, then transfer to a wire rack to cool completely.
Storage suggestion: Keep the cookies at room temperature, between sheets of wax paper in an airtight container, for up to 5 days.