Butter cookie by Soon Su-Yee

Butter cookie 
Recipe source credit to Happy Homebaker

Ingredients:
(makes about 36 pieces)

100g butter, softened at room temperature
80g caster sugar
1 egg yolk
180g cake flour
20g corn flour

Method:

Sift cake flour and corn flour together and set aside. Line baking tray with parchment paper, set aside.
With an electric mixer, add in sugar to the butter in 2 ~3 additions and cream till the mixture turns pale and fluffy.
Add in egg yolk and mix well.
Add sifted flour mixture in 2 ~ 3 additions, stir with a spatula to form a soft dough.
Place dough in a plastic bag and flatten with rolling pin.
Refrigerate the dough for about half an hour.
Remove dough from fridge. Roll out dough on slightly floured work surface and cut out with slightly floured cookie cutters. If the dough appears to be a little to hard and breaks into pieces while rolling, leave it at room temperature for a few minutes. The dough will soften up and can be rolled easily.
Bake at pre-heated oven at 175 degC for 15 ~ 20mins.
Let cool and store in air-tight container.