Preheat oven to 325 degrees F. Melt the butter and chocolate. Beat the eggs and vanilla (do not over beat). Sift and fold in the flour, mochi flour, baking powder, and salt to the butter mixture followed by the sugar. Fold in the egg mixture until incorporated. Then fold in coconut flakes. Pour into an oven proof dish or pan and bake in the oven for 15 minutes.