Note from Ricardo
Good to know
If the buttercream seems too soft, refrigerate for a few minutes, then whisk again.
This majestic pistachio cake must be made with unsalted nuts. Unfortunately, they are not sold everywhere. They are often found in health food stores. Otherwise, buy shelled salted pistachios. Simply rinse them under water and then dry in the oven for a few minutes at 180 ˚ C (350 ˚ F).