Preheat your oven to 338°F/170°C
Line two cookie baking sheets with parchment paper
In a medium size mixing bowl add the flour, baking soda, and salt and mix them together using a whisk or fork
In a separate bowl melt the butter and slightly cool it down to a touch
In a mixing bowl add the melted butter and the sugar and mix on medium speed using the paddle attachment until well incorporated about 1 minute
Add the egg and vanilla into the butter mixture and mix them until completely blended. Clean off the side with a spatula
Add the flour mixture and mix them all together on slow speed for about 45 seconds or until it all blends together and is combined
Add the semisweet chocolate chips and pecan and mix on slow speed for 20-30 seconds or until evenly incorporated throughout the cookie batter
Chill the dough for at least 30 minutes before scooping
Scoop the batter using a small to medium ice cream scoop and place them onto a lined baking sheet 1 1/2 to 2 inches apart
Press down and slightly flatten the cookie balls to about 1/4 inch thickness (6mm)
Place cookie pan into the middle of the oven and bake for 14-15 minutes or until lightly golden brown. The bottom of the cookies will be darker than the top.
Once they are baked transfer them to a wire rack and cool down the cookies, cookies will crisp up as it cools down.
You can store them in an airtight container at room ambient temperature for about 2 weeks.