Brown the butter: Set out a medium heat-proof bowl because you’ll need it at the end of this step. Slice the butter into Tablespoon-size pieces and place in a light-colored skillet or large pot. Light colored helps you determine when the butter begins browning. (See note if using a dark skillet or pot.) Melt the butter over medium heat and stir or whisk constantly. Once melted, the butter will begin to foam. Keep stirring/whisking. After 5-7 minutes, the butter will begin browning and you’ll notice lightly browned specks begin to form at the bottom of the pan. It will have a nutty aroma. Once browned, remove from heat immediately and pour into the bowl, including any solids that have formed on the bottom of the pan. (You want those solids for flavor.) Cool brown butter for 5 minutes. Don’t cool longer than that because the butter will begin to thicken and, as a result, the cookie dough will be difficult to mix and its texture will be very crumbly.

Whisk the brown sugar and granulated sugar into the brown butter and then whisk in the eggs and vanilla extract. Set aside. In a large bowl, whisk the flour, baking soda, cinnamon, and salt together. Pour the wet ingredients into the dry ingredients, add the chopped chocolate and pecans, then stir together with a large spoon or rubber spatula. Dough will be greasy, thick, and even slightly crumbly.

Cover cookie dough and chill in the refrigerator for 2 hours and up to 3 days before baking. (You can also freeze the dough balls, see Freezing Instructions below.) If chilling for longer than 2 hours, allow the dough to sit at room temperature for at least 20-30 minutes before rolling and baking in the next step. The cookie dough is quite firm otherwise.

Towards the end of chill time, preheat oven to 350°F (177°C). Line large baking sheets with parchment paper or silicone baking mats. Set aside.

Roll or scoop the dough into balls, 1.5 Tablespoons of dough each. I recommend a medium cookie scoop. Place 3 inches apart on the baking sheets and bake for 13-14 minutes or until the edges appear set. (Tip: If cookies aren’t spreading by the 10 minute mark, remove pan from the oven, carefully bang it on the counter to help induce some spreading, and then return it to the oven to finish baking.)

Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Cookies stay fresh covered at room temperature for up to 1 week.