I think its a reference to a TV show called Bob's Burgers.
So in one episode the Bob's family go trick and treating.
One of the adults points out to the children they have too much candy and they should sell some of it.
One of the smart arse children retorts that they would just end up buying more candy with the money! Then says
"Money is just candy that hasn't been born yet."
So, I think Madonna is making reference to this. What her bare boobs have got to do with it, I don't know! But that's Madonna for you.
Does she think showing her boobs is controversial?