You should get 14 good sized muffins out of this mixture. If you use an ice-cream scoop, to fill the muffin cases, you’ll get them all evenly sized. You can use different fruits, and if the berries you find or buy are a little too large, just slice them to a more manageable size to mix into the batter.
Will keep in an airtight container only for a few days as they contain fresh fruit. They will keep longer if kept in the fridge.