Upcycled Chocolate Frosting cake

I hate wasting food. Especially sweets full of expensive ingredients like butter and (very) nice cocoa. So when the chocolate frosting I'd prepared for these cupcakes -- a buttercream I've made and adored a dozen times before -- looked gritty (?!) after refrigeration, this gal weren't happy.

All stops were pulled to smooth things out. The poor frosting was heated up and cooled down, more than once. Then my poor faithful mixer was pushed to its breaking point trying to whip it into shape. And I cajoled it with some gentle hand mixing too, not underestimating the power of some personal tender lovin' care.

But days of failed attempts later, I just wanted to pull out my hair and dump the whole thing. Happily, inspiration struck. I realized that this buttercream made simply out of butter, cocoa, powdered sugar, vanilla, and cream was practically a chocolate cake waiting to happen. Gently, I stirred in 2 eggs, 1/2 cup of flour, and pinches of salt and baking powder. Twenty to twenty-five minutes in the oven at 350 degrees F made the magic happen.

So now I offer you my Upcycled Chocolate Cake, and ask what creative ways have you come up with to prevent good food from going to waste?