I have been making the House Buttercream from The Whimsical Bakehouse cookbook for quite some time. I love working with it. I love the texture and taste; however, I can never get the yield. I follow the recipe to a T in my KitchenAid stand mixer but I always end up with a scant 6 cups (instead of 9). Can anyone tell me what I am doing wrong or does this recipe contain a typographic error?

Do you think they are whipping it more?  Three cups is a lot though.  It might be an error or they just didn't test the single recipe before they printed it.

Thank you for responding. The recipe calls for 10-20 minutes of whipping on medium high. I've only whipped 20 minutes but I figured after that point that nothing is going to happen if it hasn't already. I use the whipping wisk attachment too, but no luck. I guess I better get used to having 6 cups instead of 9.

The KA wire whip with the extra wires in it do a much better job.  Super duper whipping.