Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats. This will help prevent the cookies from sticking and make cleanup easier.

In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy. I like to use an electric mixer for this step, but a hand whisk works just as well if you’re up for a little extra arm work. This usually takes about 2-3 minutes.

Once the butter and sugars are well creamed, add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract until fully incorporated.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Be careful not to overmix, as this can result in a denser cookie.

Fold in the chocolate chips and walnuts (if using) with a spatula. Make sure the chocolate chips are evenly distributed throughout the dough.

Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheets, spacing them about 2 inches apart. Bake in the preheated oven for 10 minutes, or until the edges are golden brown, and the centers are just set. Keep a close eye on them to avoid overbaking.

Once baked, remove the cookies from the oven and let them cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely. This ensures they maintain their shape and don't break apart.