ANyone know of a GOOD tasting butter cream I can use for a rustic look?

I always use either IMBC or SMBC but need to use probably one with powdered sugar (more like American BC) which I never like because they are excessively sweet and gritty compared to the meringue BCs.

But those don't lend themselves for that rustic look as seen in the cakes attached.

Any ideas?

I only use IMBC and do rustic quite often, you don't need to use a crusting recipe.