- With the rack in the middle position, preheat the oven to 180 °C (350 °F). Line two or three baking sheets with parchment paper.
- In a plate, combine 45 ml (3 tablespoons) of the sugar with the cinnamon. Set aside.
- In a bowl, combine the flour, baking soda, cream of tartar, and salt. Set aside.
- In a large bowl, cream the butter with the remaining sugar and the vanilla with an electric mixer. Add the eggs, one at a time, and beat until smooth. On low speed, add the flour mixture.
- With your hands, shape into 20-ml (4 teaspoons) balls. Roll in the cinnamon sugar. Shake to remove any excess and place on the baking sheets, spacing them about 2.5-cm (1-inch) apart. Bake, one sheet at a time, for about 12 minutes or until lightly browned. Will keep for 3 to 4 days in an airtight container at room temperature.