Place the butter and icing sugar into the bowl of your Thermomix and mix for 2 minutes, Speed 3.
Scrape down the sides and mix for a further 1 minute, Speed 3 or until the mixture is white and creamy.
Scrape down the sides of your Thermomix bowl and add the vanilla extract, cocoa powder and milk before mixing for 1 minute, Speed 3.
RECIPE NOTES & TIPSQuantity - This recipe makes enough buttercream to ice 12 cupcakes or a standard 20cm cake - such as our Thermomix Butter Cake Recipe.Pure Icing Sugar - It's important to use pure icing sugar as it results in a firmer frosting that is perfect for piping.Firmness - If your frosting is too firm, simply add an extra tablespoon of milk and mix again. On the other hand, if your frosting is too soft, add a little extra icing sugar and mix again.Room Temperature Butter - It's important to ensure that your butter has softened to room temperature before using. This will give you the smoothest and creamiest Thermomix chocolate buttercream.Storing - Once you have iced your cakes/cupcakes, place them in an airtight container and store at room temperature.Doubling - This recipe can be doubled. You will need to increase the mixing times accordingly.