In a large bowl place the butter and caster sugar.
Now with a hand held electric whisk beat on low heat until the sugar is mixed with the butter, then increase the speed and beat till light and creamy and fluffy.
Then slowly incorporate the flour and cardamom powder, vanilla extract if using and with a spatula bring it together.
Now lightly mix it with hands and gently bring the dough together into a soft dough.
Shape the dough in a disc and wrap in a cling film. Refrigerate it for 10 minutes so that the dough will firm up a bit.
Mean while Preheat oven to 180°C or 350 degrees F. And line a baking sheet lined with parchment paper.
Remove the disc from the refrigerator and roll it to 1/4 inch thickness. Cut it in your desired shape.
Put them in the oven and Bake for 10-12 minutes. Let them cool for 4-5 in the baking sheet.
Them slowly transfer them on the cooling and cool them completely.