In a large mixing bowl, cream together the softened butter, brown sugar, and white sugar until light and fluffy.
Add the egg and egg yolk to the butter and sugar mixture. Mix well until the eggs are fully incorporated. Add vanilla extract and mix again.
In a separate bowl, whisk together the all-purpose flour, corn flour, salt, and baking soda.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Be careful not to overmix.
Gently fold in chocolate chips until evenly distributed throughout the dough.
Scoop out portions of dough and shape them into balls. Place them in a container that can be placed in the freezer.
Cover the cookie dough and chill in the freezer for at least 30 minutes to 2 hours. Chilling the dough helps to prevent excessive spreading during baking and enhances the flavour.
Preheat your oven to 350°F (180°C) for 10 minutes. Line a baking sheet with parchment paper.
Place your cookie dough scoops on the prepared baking sheet with enough space between each cookie.
Bake in the preheated oven for 11-12 minutes or until the edges are golden brown. The centres may still be soft but will firm up as they cool.
Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.
Once completely cooled, enjoy your delicious homemade chocolate chip cookies!