Wild-Blueberry Yogurt Mini-Cake

This is based on the recipe for Best Blueberry Muffins in Lauren Chattman's Mom's Big Book of Baking. I used frozen wild blueberries, and yogurt thinned with water as an alternative for buttermilk, with a little cardamom added (not in the recipe, but I thought it would be nice with the blueberries). After filling up the muffin tin, there was enough batter left over to make this little cake. I like this recipe, as it's very generous with the amount of blueberries!