Preheat your oven to 350°F (175°C).

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

Add the egg and vanilla extract to the mixture and beat well.

In another bowl, combine the flour, baking soda, and salt.

Gradually add the dry ingredients to the wet mixture, stirring until well combined.

Fold in the cornflakes gently to maintain their crunch.

If using, add chocolate chips and mix until evenly distributed.

Drop spoonfuls of the dough onto a baking sheet lined with parchment paper.

Bake in the preheated oven for 10-12 minutes or until golden brown.

Allow the cookies to cool on the baking sheet for a few minutes before transferring to a wire rack.