Raspberries, strawberries, and blueberries are sweet summer treats. But they can quickly turn moldy even while in the supermarket. Buy them frozen and you can lock in the nutrients and enjoy them in season or not. Eat them straight out of the freezer. Or thaw before baking them into cobblers, muffins, or pies. Pro tip: add an extra dash of starch or other thickener to soak up the juices.