¾ cup (150g ) sugar, plus 2 tablespoons for dusting
1½ teaspoons cinnamon
12 tablespoons (170 g) unsalted butter, at room temperature
¼ cup (55 g) packed dark brown sugar
2 large eggs, 1 separated
½ teaspoon vanilla extract
Preheat the oven to 375°F. Line a cookie sheet with parchment paper.
In a medium bowl, stir together the flour, baking soda, and salt.
In a small bowl, combine 2 tablespoons (25 g) of sugar and cinnamon.
Use a standing mixer fitted with a paddle attachment, cream the butter, ¾ cup (150 g) of sugar, and the brown sugar for 2 minutes, scraping the sides as you go. Add the egg and separated egg white and the vanilla. Beat on medium-low for 1 to 2 minutes until combined. Add flour mixture and beat on medium-low speed until the flour is incorporated. Refrigerate for 60 minutes.
Roll 1 heaping tablespoon of dough into a ball in your hands, then roll in the cinnamon sugar to dust completely. Place on the baking sheet, 2 inches apart. Refrigerate the remaining dough.
Bake for 10 minutes until edges are golden and the center is soft but cooked through. Repeat with the second batch.
Let cookies cool for 10 minutes. Transfer to a cooling rack until they have firmed up.