Now, this makes more sense, as I can see that with an inventory adjustment I will see the cost in the donations account.

If I would still want to use an invoice, I could set up my donation item with the COGS account pointing to the Charity/Donations account, thus, I don't have to make a journal entry to move from COGS to the donations account.

One more question, we also donate non-inventory items, like free drinks, for which my item does not have any cost. For testing I added those to an invoice with a sales price, but it posted as a negative amount to the Charity/Donations account, thus, reducing the total donation amount.