Preheat oven to 325° F and combine butter and sugars. Beat well until fluffy.
Add eggs, one at a time, and mix just until combined.
Add vanilla, salt, and oats and mix lightly.
Sift (or whisk) the flour, and baking soda together so there are no lumps. Add the dry ingredients to the dough and mix gently but don’t overmix.
Add the chocolate chips (and nuts if using) and fold them in.
Scoop dough out using 1/4 cup measuring cups, and roll into balls. Lay six dough balls on a cookie sheet lined with parchment paper.
Bake for 10 minutes or just until edges are set. Do not overbake! Remove from the oven and transfer to a cooling rack. Repeat with the rest of the dough.
Very important and extremely controversial: for optimal chewiness, let cookies cool completely! If you’re less into chewiness and more into doughiness, then disregard my advice. But as the self-proclaimed president of the chewy-cookie-fan club, let them cool and the texture will only get better!