1. In a large mixing bowl whisk butter with electric beaters (you can also use a stand mixer), work for at least 5mins so butter is super fluffy to start.
2. Add in a little at a time the icing sugar, each time incorporating well with the mixer. You may need to use a spatula to scrape down the sides. Once all sugar is fully incorporated add the lemon, milk and vanilla paste. Beat well to combine.
3. Use icing for your cupcakes (GET THE RECIPE HERE) or to ice your fav cake...