Preheat the oven to 350°F (175°C). Grease a baking pan.

In a mixing bowl, combine flour, brown sugar, melted butter, egg, vanilla extract, and salt. Mix until well combined.

Spread the mixture evenly in the prepared baking pan.

Sprinkle chocolate chips and nuts (if using) over the base mixture.

Bake in the preheated oven for 25 minutes or until golden brown.

Allow to cool before cutting into bars.