Preheat oven to 350 F. Line baking sheets with parchment paper. Set aside.
Brown the butter in a skillet over medium heat. Quickly remove from heat when it smells nutty and turns a light golden brown color, about 5 minutes.
1 cup unsalted butter
Pour the browned butter into a large mixing bowl, scraping the browned bits at the bottom.
Let cool to room temperature for about 20-25 minutes.
Once butter has cooled to room temperature, add brown sugar. Whisk until well combined.
⅔ cup light brown sugar
Add maple syrup, egg yolks, and vanilla. Whisk again to combine.
½ cup pure maple syrup, 2 large egg yolks, 1 teaspoon vanilla extract
Add flour, baking soda, salt, and cinnamon. Mix until just combined. Don’t overmix.
1 teaspoon baking soda, ½ teaspoon kosher salt, ¼ teaspoon ground cinnamon, 2 ¼ cups all purpose flour
Stir in chopped pecans.
1 cup chopped pecans
Scoop cookie dough into 1 ½ tablespoon portions. Roll into a ball.
Place each ball of dough about 2 inches apart on the prepared baking sheets. Top with additional chopped pecans, if desired.
Bake for about 8-11 minutes, or until the edges are set. Sprinkle tops with flaky sea salt. Let cookies cool completely on the baking sheet.
Notes
Butter: If you would like to use salted butter, decrease the salt to 1/4 teaspoon.
Brown sugar: You can substitute dark brown sugar for richer flavor in the cookies.
Maple syrup: The maple syrup adds light sweetness and moisture to the cookies.
Flour: It’s important to properly measure the flour. I recommend weighing the dry ingredient for the most accurate measurements (click "metric" just above the ingredients for the weights). If not, you can stir or sift the flour to break it up, lightly spoon it into the measuring up, and then level. Avoid packing the flour as that will give you dry or dense cookies.
Pecans: For even more flavor, you can toast the pecans before use. If toasting, let them cool before use.