Who should checks be written to purchase cashier checks? Payable to the bank or payable to person purchasing the cashier check?

Payable to the bank. The customer is purchasing a negotiable instrument.

I disagree. A dishonest business employee can make checks payable to the bank telling their employer that they are making loan payments and instead purchase cashier's checks and a good lawyer will sue the bank for being culpable in not applying the checks appropriately to the business' loan.

If your customer wants to purchase a cashier's check they either make their check payable to cash or to themselves. Even better, have a separate ticket/trancode for a monetary instrument purchase which requires a customer/authorized signer signature.

agree with Brian, we use a separate tran code for these