Preheat your oven to 350°F (175°C). Grease a 9×13 inch baking pan with butter or non-stick spray, or line it with parchment paper for easy removal later.
In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar together until the mixture is light and fluffy. This usually takes about 2 to 3 minutes with an electric mixer.
Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract until fully incorporated.
In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add this dry mixture to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Use a spatula to gently fold in the chocolate chips and the chopped pecans. Ensure they are evenly distributed throughout the thick dough.
Transfer the dough into the prepared baking pan. Use a spatula or your hands to press it evenly into the corners. Bake for 22 to 27 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out mostly clean.
Place the pan on a wire rack and allow the bars to cool completely before cutting them into squares. This ensures they set properly and don’t crumble.