I used this one too, but I doctored up .
added 1-2 stick of butter( creamed butter & about 1 cupcrisco together till well blended )
I also added a little corn starch( cuts down on the sweetness,I use to buy 100 LBs. bakers sugar and that had it in it .with the 2 LB. 10X (powder sugar )
add heavy whipping cream last ( 1/2 pint or more till the consistincy you want .)I also used almond flavoring sometimes or the clear Vanilla ,a pinch of salt I also used my Kitchaid mixer and let it go . Comes out like a whip cream icing . Good luck to you