One of the big things to get around the connection between reward and dessert is to simply say the child ran out of time. That is what happens at my daycare and kids learn to talk less and eat faster too. After a reasonable amount of time and we are talking lunch taking an hour from come sit to wash and go so plenty of time is allowed and as they finish totally they go take off their shoes for nap and are allowed to watch tv - totally works as an incentive to eat faster too. Then I call them one at a time for potty/diaper, tuck in the little ones that go upstairs to playpens and then send the rest to their nap mats - love that the kids shows are often only 15 minutes long so I can wait till the end of the show. It's just what works here and makes for a smooth transition.