I've always made my IM buttercream from the same recipe--basically 2.5c sugar, 6 egg whites, 20 oz. butter, flavoring of choice. Last night I was making a batch for my son's birthday cake, and realized that I would really prefer it with less butter. Perhaps (gasp) significantly less butter.
I've got some baking books I could consult to see what ratios they use, but I'm wondering if anybody has any feedback on what happens as you decrease the amount of butter. I mean, fundamentally, you get meringue, I know that. I'm assuming that italian meringue isn't sufficiently stable (without some baking at low temp) to 'frost' a cake with? Plus, I don't think that's quite what I'm after, I just want less butter. Is the frosting reasonably stable with, say, half the amount of butter? Does it alter how much flavoring liquid (extract, etc.) I can put in?
Any advice/thoughts appreciated.