Preheat oven to 375 degrees F. Place parchment paper on two baking sheets; set aside.
In a medium bowl, add flour, salt and baking soda. Whisk together to combine.
Using your stand mixer with the paddle attachment, cream butter and both sugars until fluffy, about 3 minutes. Add eggs, one at a time and mix until fully incorporated. Add in vanilla extract and cocoa powder.
Slowly add the flour mixture to the butter mixture. Mix until just combined.
Using a ladle, stir in the white chocolate chips and walnuts, if using.
Drop dough by the tablespoons onto prepared baking sheets. Bake 10 minutes.
Remove cookies to a wire rack to cool. Enjoy!