These homemade wonton cups can be kept in a tightly sealed baggie for up to 24 hours. They don’t last much longer than a day and lose their crispness the longer they sit on your counter, so your best bet is to eat them as soon as possible. If you’re making these baked wontons for a party later in the day, go ahead and make them the morning or afternoon of the event. These wonton cups will be fine that same night!