Roasted blueberry frozen yogurt. Yes, believe it. Blueberries are roasted with sugar in the oven, which intensifies their flavor. The berries are then swirled into lightly sweeetened yogurt and then churned in an ice cream maker.
*Can you just freeze yogurt to make frozen yogurt?
Sure, you could. Just like you could make lemonade by jamming a straw into a lemon. Close...but not quite. Both of these scenarios are missing a key ingredient—sugar. If you just freeze plain yogurt and berries, you're going to end up with a solid block of gritty dairy as soon as you put it in the freezer. You'll need to add sugar, in order to freeze it into something scoopable. As with sorbet and ice cream, the more sugar you add, the softer it will be.