Line a bakiing sheet with parchment paper.
In a medium sized bowl, combine the sugars, butter, egg, and vanilla. Stir with a whisk until fully combined.
½ cup packed dark brown sugar, ½ cup sugar, ½ cup browned unsalted butter, cooled, ½ teaspoon vanilla, 1 egg, room temperature
In a separate medium sized bowl, combine the oatmeal, flour, baking soda, baking powder, and salt. Stir with a whisk to combine.
1 ½ cups oatmeal, ¾ cup flour, ½ teaspoon baking soda, ¼ teaspoon baking powder, ¼ teaspoon salt
Add the oatmeal mixture to the sugar mixture and stir just until almost combined. Add the pecans and chocolate chips and stir just until you no longer see any dry flour.
½ cup pecan pieces, ½ cup extra dark chocolate baking chips
Using a cookie scoop, place dough on prepared cookie sheet. Place in the refrigerator for 30-45 minutes.
Preheat oven to 350°F.
Bake cookies 2 inches apart on parchment lined baking sheet for 12-14 minutes, or until just starting to brown around the edges. Remove from oven, sprinkle with flake salt and let cool for 2 minutes before transferring to a wire rack to cool completely.