Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats.
In a large bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.
Beat in the egg and vanilla extract until fully combined.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Stir in the chocolate chips and chopped pecans until evenly distributed throughout the dough.
Drop tablespoon-sized scoops of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are golden brown and the centers are still soft.
Remove from the oven and let the cookies cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.