Place the softened butter cut into pieces in the bowl of your stand mixer fitted with the whisk attachment and whisk at high speed for about 3-5 minutes until you obtain a smooth and creamy mixture.
Lower the speed of the mixer and add the sifted confectioner's sugar in several batches until completely incorporated.
Add the vanilla extract and full-fat heavy cream and beat on high speed for a further 5 minutes until you have a smooth, voluminous frosting.
Beat the whipped buttercream with a rubber spatula or the flat spatula of your stand mixer for 2 minutes at low speed to evacuate air bubbles and obtain a smooth frosting.
Use immediately on your cakes or store in the fridge under plastic wrap.
