I usually work with American buttercream which I assume would work just fine to create the rose swirl type cake but I've never made this cake before. Would American buttercream be the best choice or do you think IMBC or SWMB would work fine as well.
Have any used a merengue buttercream to decorate this type of cake before? I much prefer the taste compared to American buttercream.
It sure will.
IMBC will be perfect. Just don't let it get warm while you are decorating. Like ABC, there are optimum textures for the best swirl. In ABC, you adjust by powdered sugar and water. In IMBC, you adjust by temp.
Personally, I find it best to work with when it is freshly made.
This is a tip I use that I haven't seen on CC. When I first learned FBC, the recipe called for 1 tsp boiling water. It makes the buttercream not only smoother, but it actually shines. It works on IMBC too. Only do this just before decorating and don't do it if the buttercream is too soft already.