Preheat the oven to 350°F (175°C) and grease a baking dish.

In a mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth.

Beat in the eggs one at a time, then stir in the vanilla extract.

In another bowl, whisk together the flour, baking soda, and salt.

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

Fold in the chocolate chips and nuts if using.

Spread the batter evenly in the prepared baking dish.

Bake in the preheated oven for 20-25 minutes, or until the edges are golden and a toothpick inserted in the center comes out clean.

Allow to cool in the baking dish before cutting into bars.