In a large mixing bowl, beat the butter until smooth and creamy (approx. 5 minutes). Alternatively, use an electric mixer, either hand-held or standing to make it easier.
Add the salt, vanilla and if you are making a chocolate buttercream add the cocoa. Mix until well combined and smooth, stopping to scrape down the side of the bowl a couple of times.
Gradually sift in about half of the icing sugar with 2 tbsp of cream and mix until well combined and smooth. Scrape down the sides of the bowl as needed.
Add the remaining icing sugar and mix until smooth and creamy.
Getting the best consistency depends on what you are going to be frosting. Check out my recipe tips section on the right consistency needed for piping or frosting.
For a stiffer frosting add a little more icing sugar. If the frosting is too thick, add a little more cream, beating after each addition until the desired consistency is achieved.
This recipe makes enough frosting for 6-8 cupcakes/muffins or a 2-layer 20cm (8") cake. Total weight 490g vanilla buttercream or 530g chocolate buttercream.