Preheat the oven to 375F

Soften the butter at room temperature for at least 20 minutes

Combine the flour, baking soda, and salt in the small mixing bowl

Beat the butter, sugar, brown sugar, and vanilla in the large mixing bowl

Add the egg to the mixture

Beat the mixture until the egg is blended in

Add the flour mixture, chocolate chips, and pecan pieces to the large bowl

Beat until all the ingredients are well-combined

Spray the baking dish with cooking spray

Spread the cookie mixture evenly in the baking dish

Bake in the preheated oven for 20 minutes

Remove the baking dish from the oven

Allow the cookies to cool for at least 30 minutes

Cut the cookies into squares