Afaik you can only set this up using the vSphere Web Client. Although the Windows based vSphere Client is still available, new features are only added to the Web Client.
André
So I need to use vCenter to create VMs with more than 32 cores?
Yes, at least for some of the new settings. However, you can also try to edit the VM's configuration (.vmx) file manually. After editing it, you either need to remove/add the VM from/to the inventory or reload it form the command line (see VMware KB: Reloading a vmx file without removing the virtual machine from inventory) in order for the changes to take effect.
André