If you use larger berries, like blackberries, slice them in half; otherwise they'll be too large. (vegan-magazine.com)
This amount of chocolate will cover about 18 fairly large berries. (kingarthurflour.com)
Larger berries make the batter stand up higher when you flip them so you need to push the mixture down with your spatula and maybe even squash the berries slightly to get the batter to make contact with the fry pan. (ambitiouskitchen.com)