Cream the butter and sugars

• Beat the softened butter with the brown sugar and granulated sugar until light and fluffy.

Add the eggs

• Beat in the eggs one at a time until fully incorporated.

Mix the dry ingredients

• Whisk the flour, cornstarch, baking soda and salt together in a separate bowl.

Form the dough

• Fold the dry ingredients into the wet mixture until just combined.
• Stir in the chocolate chips and chopped walnuts.

Shape the cookies

• Divide the dough into large balls and place them on a lined baking tray.

Bake

• Bake at 180 °C until the edges are golden and the centers are still soft.

Cool

• Let the cookies cool on the tray so the centers set.