In a bowl, whisk the ghee and sugar till nice and fluffy.
Add the cardamom and kewra essence and whisk well.
Add in the flour, custard powder, baking soda, salt and crushed cashewnuts and fold using a spatula till it forms a dough. Add a tablespoon of milk if finding it difficult to shape.
Plop the dough onto cling film and shape into a log. Roll tight and refrigerate to set for an hour.
Preheat oven to 180 degrees. Line a baking tray with parchment paper.
Take out the roll and remove the cling film. Slice into 1/2 inch thick cookies and layer on the tray with some spacing in between. Gently press down a half of a cashewnut on each of the cookie.
Bake for around 12-15 minutes till just golden brown. Take out and cool on a rack. The cookies harden as they cool.