With an electric mixer, beat butter, sugar and a pinch of salt until light and fluffy.

Sift flour, corn flour, baking powder into the butter mixture and fold well with a rubber spatula.

Stir in the mashed salted egg yolks and use hand to knead to form to a soft dough (do not over knead). Wrap dough in cling wrap and allow it to rest in fridge for at least 30 minutes.

Line baking trays with baking paper and preheat oven to 170 deg C.

Roll dough with some dusted flour into 3mm thickness between 2 plastic sheets and return it to the fridge for 5-10 minutes to harden, before cutting them into shapes using your desired cookie cutter.

Brush the cookies with egg yolk and sprinkle sesame seeds on them and bake for about 15 minutes or until golden brown.

Cool down cookies completely before storing into an airtight container.