*makes around 2 cups of buttercream
115g unsalted butter - room temperature
110g margarine - room temperature
2 cups icing sugar - sieved
1/2 tsp salt
1 tbsp vanilla essense
some milk (if necessary)
1. Cream butter, margarine, vanilla essence and salt till pale and fluffy.
3. Add in sieved icing sugar by 2-3 portions and mix until well-combined.
6. Add milk by the teaspoon (if needed) until reach desired consistency.