In a saucepan, melt and brown the butter until the colour turns brown and all water evaporates. Let it rest at room temperature.
In a bowl, add the brown butter, caster sugar, brown sugar, curd/yogurt and vanilla extract. Mix well.
Sift in the flour, corn starch and baking soda. If the butter is unsalted, add ¼ tsp salt. Using a spatula, fold gently.
Divide the dough into balls of 80g each and chill overnight in the freezer or refrigerate for a couple of hours.
Bake at 180°C for about 12-13 minutes. Remove when slightly undone to achieve a soft, chewy texture.
