Have made 12 cupcakes following a Hummingbird Bakery recipe, and it advises making buttercream icing with 500g of icing sugar (160 g butter and 50 ml tea-infused milk) - that sounds like a HUGE amount to me and I am considering starting with half quantities. I don't usually use buttercream, so please reassure me that half a kilo of icing sugar is a normal amount...