I agree that communication is very important. If I gave my SO coupons like that, I'd want him to appreciate all of them, not the just the ones for sexual favors. So, perhaps use the candlelit dinner one first.
As for your "day of whatever you want to do," I suggest telling her first some of what you would like to do. Ask her if she is turned off by oral. If not, since you are new to it, maybe ask her how she likes it. In my experiences, sex has never been that great unless it can be talked about. Do this first, then we'll talk about food.
Just kidding... I haven't used any food products besides whipped cream, and if things are hot and heavy like they're supposed to be, the whipped cream just gets warm, and in my opinion, warm whipped cream isn't tastey... could be just me though.