Preheat your oven to 350°F (175°C).
In your mixing bowl, combine the softened butter, granulated sugar, and brown sugar. Cream them together until light and fluffy, about 2-3 minutes.
Add the eggs one at a time, mixing well after each addition, then pour in the vanilla extract. Mix until fully incorporated.
In a separate bowl, whisk together the flour, salt, and baking soda. Gradually add this mixture to the wet ingredients, mixing just until combined.
Gently fold in the semisweet chocolate chips, white chocolate chips, and chopped walnuts (if using).
Transfer the cookie dough onto a lined baking sheet and shape it into a large disc, about 1 inch thick.
Bake for 20-25 minutes, or until the edges are lightly golden and the center is set but still soft.
Let it cool on the baking sheet for about 10 minutes before transferring it to a wire rack.
