Melt in the mouth butter cookies

Original recipe from Cook.Bake.Love
This cookies really nice, soft, fragile and melt in the mouth.

Ingredients:
125g butter, soften at room temperature (I used salted butter)
40g icing sugar
125g potato starch
80g superfine flour (can be replaced by plain flour)

Method:
1) Beat butter and icing sugar till fluffy and lighter in colour, sift in potato starch and flour, mix to form a soft dough.
2) Roll into small ball, arrange on lined baking pan and press lightly with a fork. Bake in preheated oven at 150C for 20 mins, upper rack (need not bake till cookies turn brown).

Note:
1) I measured each cookie dough with ½ tbsp measuring spoon
2) To prevent cookie dough from sticking on fork, dip the fork in water before each use.
80g superfine flour (can be replaced by plain flour)

Method:
1) Beat butter and icing sugar till fluffy and lighter in colour, sift in potato starch and flour, mix to form a soft dough.
2) Roll into small ball, arrange on lined baking pan and press lightly with a fork. Bake in preheated oven at 150C for 20 mins, upper rack (need not bake till cookies turn brown).

Note:
1) I measured each cookie dough with ½ tbsp measuring spoon, made 62pcs. I think the size is just nice.
2) To prevent cookie dough from sticking on fork, dip the fork in water before each use