Melt butter on low heat; set aside to cool. Remove and discard husks from about ¾ container of berries. Rinse well, then quarter. You should have a bit more than ¾ cup fruit. Add more to make that amount, if necessary. Sift together flour, ginger, coriander, and cinnamon. Butter and flour 9-inch square pan.
In medium bowl of electric stand mixer beat eggs, yolk