Preheat oven to 350°F/190°C

Put 113 g of unsalted butter into a mixing bowl, then add 60 g of sugar and 1/4 tsp of salt. Fold in with spatula until the sugar is fully mixed with the butter, then use electric mixer until. The butter becomes slightly creamy.

Add 1 egg yolk, mix again just until the yolk mixed, add 1 tbsp of heavy cream and 1 tsp of vanilla extract, mix again until fully mixed.

In a separate container, mix 125 g of cake flour with 2 tbsp of cornstarch

Shift the flour mix into the butter mix (in two batches), use the mixer to completely mix everything.

Transfer the processed dough into piping bag, use star shaped tip. Lie baking paper on top of the pan.

Shape the dough into round shaped cookies, then bake for 15-18 minutes