I was wondering if you can make the SMBC and IMBC using meringue powder? Has anyone tried?
I'm not sure what meringue powder is - if it is just dried egg white, then yes. Dilute the egg white and continue in the normal way. If it is egg white and sugar, then you could not make italian meringue buttercream - which is the one I make - because the egg white and sugar are kept separate for half the process. You might be able to make the Swiss one because I think you cook the sugar and egg together. Worth trying. Although I am always trying to use up egg whites. And because you are cooking the egg white in both, there is not the same risk of salmonella as there is with royal icing.