In a stand mixer using the paddle attachment, or in a medium bowl using a hand-mixer, beat together the butter and sugars (both dark + granulated) for about 3 minutes until well combined and pale in color. 

To the bowl, add the egg, egg yolk, and vanilla extract. Beat to combine for about 1 minute. 

In a separate bowl, combine the dry ingredients - flour, baking soda, salt, cinnamon. Gently mix together. 

In increments of three, add the dry ingredients into the wet until combined and a dough forms. 

Grab a parchment lined baking sheet and roll the dough into 2 tablespoon size balls. Roll through the additional ¼ cup sugar + 1 teaspoon cinnamon, and place on the baking tray. They can be touching here. Put in the fridge for at least an hour, up to overnight. 

When ready to bake, take your cookies out of the fridge and allow them to come down closer to room temp while you preheat your oven to 350℉. Bake the cookies on a parchment lined baking sheet for 14-16 minutes. Allow them to cool on the baking sheet. 

Enjoy!