Preheat your oven to 350°F (175°C).

In a medium bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon (if using). Set aside.

In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar using an electric mixer for 2-3 minutes until light and fluffy.

Beat in the vanilla extract and eggs, one at a time, mixing well after each addition.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Fold in the semi-sweet chocolate chips, white chocolate chips, and walnuts (if using).

Drop rounded portions of dough onto prepared baking sheets, leaving about 2 inches between each cookie.

Bake for 10-12 minutes until edges are golden brown and centers look slightly underbaked.

Allow cookies to cool on baking sheets for 5 minutes before transferring to wire racks to cool completely.