1Preheat oven to 160 deg C.
2Steam the salted egg yolks for three minutes, then mash with a fork to get coarse bits and set aside.
3In a mixing bowl, sift plain flour, cornflour, baking powder, milk powder and salt. Set aside.
4With an electric mixer on medium speed, cream unsalted butter, caster sugar and icing sugar until the mixture turns light and fluffy. Add mashed egg yolks and flour mixture. Mix to form clumps of dough (right). Gather the clumps to form a ball.
5Wrap the ball in cling wrap and refrigerate for about 20 minutes. Line baking tray with parchment paper.
6Roll the dough until it is 5mm thick (right). Cut out shapes using a cookie cutter and place on the baking tray.
7Gently brush the top of each cookie with the lightly beaten egg yolk and sprinkle some flaxseeds on each cookie.
8Bake for 10 minutes till they turn golden brown. Let cookies cool completely before storing them in an airtight container.
Photo and text: Straits Times/Kenneth Goh