To Prep
Combine Ingredients A in a mixing bowl and mix well. Alternatively, use an electric mixer to beat mixture for a couple of minutes, until fully combined and fluffy. Be careful not to over beat.
Add Ingredients B into a bowl, then, use a spoon to push and sift mixture through a medium coarse sieve.
Now, combine A and B until the flour mixture is totally absorbed into the butter mixture. Cover mixing bowl with cling wrap and leave to rest in the refrigerator for 30 mins.
Preheat oven to 170°C and line baking trays with baking paper.
Lightly dust surface with flour. Take a handful of the dough, and roll into 3-4mm thickness and use a cookie cutter to cut into individual cookies.
To Cook
Arrange cookies on the baking tray and brush with egg yolk. Sprinkle with sesame seeds and bake for 15 mins, or until golden brown in the oven preheated to 170°C.
Transfer cookies to a wire rack to cool completely before storing in an airtight container.