Pesachim 120 - Dessert
The rule is that no dessert is served after eating the Passover offering. However, there are many ways to understand it. Some say that only one’s favorite meats may not be eaten, because they would overpower the taste of the Passover sacrifice. Others, however, cite a different reason for the prohibition: one should not eat the sacrifice in two places, and if he were allowed desserts, then eventually he would come to eat them in a different place, and then perhaps even go to a different room with the Passover meat too.
Today there is no Passover offering, and eating matzah takes its place. Can one eat a dessert after that? Some say that since the taste of the matzah is weak, any dessert will overpower it, and so any dessert is prohibited. Others, however, read the above rule differently: "No dessert is served after the Passover offering" - only after the offering you cannot serve dessert, but after the matzah you can.
If some of the members of the Seder fell asleep and then woke up, they can proceed; however, if all of them fell a sleep, then on waking they cannot eat the Passover any longer, because it looks like eating in two different places, which, as we said above, is forbidden. If they merely dozed off, they can proceed. What is meant by dozing? - Not quite asleep but not quite awake; if they call him, he responds, but cannot command a thoughtful answer; however, if they remind him and ask for a yes or no, he can reply.
Art: Old Woman Dozing by Nicolaes Maes