Combine the flour, baking soda, and salt;(cocoa powder optional) stir into the butter mixture until well blended.
In large bowl, beat butter, sugar, eggs, and vanilla until light and fluffy.
Mix in 1-2 cup of chocolate chips or walnuts.
Preheat oven to 350 degrees F (175 degrees C).
Bake for 10-12 minutes in the preheated oven, or just until set. For other option, chill the dough for hours/overnight or so before baking as this prevents a flat cookie.
This is the experiment using different baking pan. The cup cake baking pan does make cookies taste like crispy cup cake.
The best result is still the flat baking pan.
Cool slightly on the cookie sheets before transferring to wire racks to cool completely.