What's a good dessert I can make with fresh oranges that are very tart?

We’re having a hard time eating them fresh because they’re so tart! So I thought I’d make something with them that would sweeten them up so they don’t go to waste. I was thinking about something like this, but I’m not set on it. Any different ideas? I’m looking for something in which the orange is the star of the dish because I have at least 5 of them.