Thicker batters, such as Pound Cakes , do better. I like to use frozen blueberries which are just perfect. Whether fresh or frozen, in a separate bowl, I always crush a quarter of the blueberries first, and then quickly stir them into the batter. I then quickly fold in the remaining blueberries whole. The Jordan Marsh Blueberry Muffin Recipe is an example of this. .
Fresh berries make a lovely accompaniment for any dessert.
Their slight acidity helps balance the sweetness of fillings and icings. The problem with berries is that they bleed color and water, especially when overripe. Raspberries and blackberries tend to be more fragile. So the less they are handled, the better. Because berries bleed, when making a tart filled with pastry cream and topped with them, assemble it as close to the event as possible.