I’m so sorry to hear the cake was not what you’d hoped it would be but it sounds as though you saved it!
I wasn’t aware the candies might dissolve in the batter…..I wonder what they use in confetti cakes and what the ingredients are that prevent them from dissolving !
If you’re now considering a chocolate cake with glaze, I have had recent experience with the chocolate cream glaze from the cake bible. I made the double-chocolate whammy groom’s cake in a guitar-shaped pan and needed to seal it with something (I’m not particularly adept with a piping bag so decorating it with buttercream was out of the question ). Rose’s lacquer glaze requires a perfect surface so I used the chocolate cream glaze which is really just a thin ganache. My cake had a very imperfect surface and the glaze filled in those imperfections nicely. I used only 1 coat, a second would have provided a nicer finish. I’ve included some photos (before and after glazing) to give you some idea of the coverage it provides and the finished sheen.
There’s also the cocoa syrup from the black chocolate party cake (RHC) to consider - it doesn’t provide coverage, but leaves a beautiful, shiny surface.
Click thumbnail to see full-size image