AHere's the situation - we recently held a service auction at church to raise money for an upcoming youth camp. I offered to teach a cake/cookie decorating class. I printed out pictures of different fondant techniques and royal icing techniques that I thought people would want to learn. After the auction, I emailed the lady who bought the class and asked which techniques she was interested in. She said she would never use fondant or royal icing. and that what she really wanted to learn was how to do several buttercream techniques (she sent pictures of ombre ruffles, rosettes, the rustic buttercream look). She said that she is frustrated because she has tried many times to create these looks, and the cakes never end up looking like the picture.

Here's my problem. I really haven't worked much with buttercream as a decoration. I am willing to do some research and practice before the class to help her, but I don't want to waste a lot of money trying out ingredients for something I don't think I will use much in the future. I have a feeling the problem she's had is using an American Buttercream, and the cakes she's looked at (I think) were decorated with a meringue buttercream. I have made meringue buttercream once (I can't remember if it was Swiss or Italian), and I REALLY didn't like it. The process was long, and I really disliked the overly-buttery taste.

My question is: What do you think would be the best frosting to use for this? Is it possible to create the pretty rosettes and ruffles without using a meringue-based buttercream? I ran across a recipe for "Ermine Frosting" that is supposedly silky and creamy (not gritty like American buttercream). Have any of you used it, and do you think it would be good for piping?

I know I could just tell her that I haven't worked with buttercream very much and try to get her to choose another technique, but I feel bad that she paid for a class thinking that she was going to learn how to make these pretty buttercream cakes.

If the pictures that went along with the description were of fondant cakes and techniques, then the purchaser shouldn't expect anything different.  I would explain the situation to her and tell her you're just not that experienced with the techniques she thought she was going to learn.  If it's something that interests you, you might offer to work along with her so you can both learn the techniques.  If she gets to come play "cake" with you for the day and learns a thing or two I'm sure she'll be happy - it seems like a good compromise.

Now, to answer your real question - I only use two buttercreams in my shop - an all-butter ABC and a French meringue buttercream.  And I don't think there's anything I can do with one that I can't do with the other.  They're pretty interchangeable from a decorating standpoint.  I make rosettes and ruffles with my ABC just fine.

I agree with Cup a Dee, just about any buttercream will work - it's the consistency & thickness that makes it easier or harder to make flowers, etc. I use "American" buttercream and whip the crap out of it to get the gritty out. You'll do fine just practice before hand like you said and she'll never know! 

Cupadeecakes and DkItll, thank you both so much for your advice and tips. I feel so relieved right now. I am really happy that ABC should be fine for the techniques she wants to learn. Time to get practicing. Again, I really appreciate the help from you both.

Some 95% of my decorating career was in b'cream (check out my album on this site).  This is one of the recipes I used over the years.  Hope it helps  you. http://cakecentral.com/a/2-icing

Thank you for the recipe, Kakeladi! I will try it this week!