Brown the Butter: In a light-colored saucepan over medium heat, melt the 2 sticks of unsalted butter. Swirl the pan occasionally as it foams and sizzles. After 5 to 6 minutes, dark golden specks will form on the bottom and a sweet nutty aroma will emerge. Immediately pour the browned butter into a shallow heatproof bowl (scraping all brown specks) and chill in the fridge for 20 minutes until it cools to a soft spreadable paste.

Prep the Oven & Baking Sheets: Preheat your oven to 350°F (175°C). Line two large rimmed baking sheets with parchment paper.

Cream Butter and Sugars: In a large mixing bowl, beat the cooled browned butter, granulated sugar, and brown sugar with a hand mixer or stand mixer fitted with paddle attachment for 2 minutes on medium speed until fluffy and well combined.

Add Eggs & Vanilla: Beat in the whole egg, egg yolk, and vanilla bean paste until silky smooth and creamy.

Combine Dry Ingredients: Whisk together flour, cream of tartar, baking soda, and fine sea salt in a separate bowl. Gradually fold the dry ingredients into the wet mixture on low speed until just combined into a soft, tender cookie dough. Do not overmix.

Make Cinnamon Sugar Coating: In a small shallow bowl, stir together granulated sugar, coarse turbinado sugar, and ground cinnamon.

Roll & Coat: Using a medium cookie scoop (2 tablespoons / 45g portions), roll dough into smooth round balls. Generously roll each ball in the cinnamon sugar mixture, pressing lightly so the coating adheres thoroughly on all sides.

Bake to Chewy Perfection: Arrange dough balls 2.5 inches apart on prepared baking sheets. Bake at 350°F for 9 to 11 minutes—edges should be set and lightly golden, while centers remain puffed and soft. Do not overbake!

Pan-Bang & Cool: Immediately upon pulling from the oven, give the baking sheet a firm tap against the counter to create signature crinkly ripples. Let cookies rest on the warm baking sheet for 5 minutes, then transfer to a wire cooling rack to settle into their chewy decadence.