I got an order for a gluten-free, soy-free and dairy-free cake. The cake part is no problem, but I'm having issues with the buttercream. I have Spectrum shortening and Earth Balance soy-free margarine but the soy-free margarine definitely doesn't act the same as the regular Vegan Earth Balance. I used 1/2 cup of shortening, 1/2 cup of earth balance, 1 lb of powdered sugar and 2 tbsp. coconut milk. The buttercream is ok, but definitely not quite firm enough for piping fine details and almost has a curdled appearance, not nice and smooth and creamy like a regular buttercream. I'm tempted to just use all shortening, but not sure how that would taste.
Go with a Swiss meringue buttercream, it will behave much better than a vegan American buttercream.. :)
Oh I just use spectrum organic palm shortening for the Swiss Meringue Buttercream
I just made some last night, because I don't eat dairy or soy, turned out sooo yummy & silky!! The only thing is it will get SUPER hard in the fridge, so bring it to room temp before serving :D