How can I make my brownie cookies thick instead of flat?

[Kento Nanami]

I like my brownie cookies to be thick and chewy, but every time they turn flat. How do I thicken them? Were there any tricks or some sort of ingredient which might assist?. Much appreciated for any advice in advance.

 

[hoyeon]

I think chilling the dough before baking helps them hold their shape, though it takes a bit more patience!