In a light-colored pan, melt 1 cup of unsalted butter over medium-high heat.

Cook for about 5 minutes, stirring frequently, until brown bits form at the bottom and the butter has a nutty aroma.

Remove from heat and allow to cool for 35-45 minutes. To speed up cooling, place in the refrigerator for the last 15 minutes.

Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a mixing bowl, combine cooled brown butter, granulated sugar, and brown sugar. Mix until light and fluffy.

Add 1 egg and mix until fully incorporated, then add the egg yolk and vanilla extract.

In a separate bowl, whisk together flour, salt, and baking soda.

Slowly add the dry ingredients to the wet ingredients and mix until just combined. Avoid overmixing.

In a small bowl, mix ½ cup sugar and 2 tbsp cinnamon.

Scoop out 80g (about ¼ cup) of dough and roll into a ball.

Coat each dough ball in the cinnamon-sugar mixture.

Place on a baking sheet and chill in the refrigerator for at least 1 hour (or up to 72 hours for deeper flavor).

Place 4 cookie dough balls on a baking sheet at a time.

Bake for 13-14 minutes until edges are golden brown but centers remain soft.

Allow cookies to cool on the baking sheet for 3-4 minutes before transferring to a wire rack.