This has sort of existed since the '40s, using radiant heat from the bread: http://www.automaticbeyondbelief.org/ http://www.automaticbeyondbelief.org/ I haven

This has sort of existed since the '40s, using radiant heat from the bread: http://www.automaticbeyondbelief.org/ http://www.automaticbeyondbelief.org/ I haven't tested this, but you're probably have issues with e.g. dark rye.