yellow and orange food colouring pastes or gels
350g/12oz plain flour, plus extra for rolling
陆 tsp baking powder
150驳/5陆辞锄 icing sugar, sifted
500g/1lb 2oz royal icing sugar
pinch salt
1 tsp vanilla bean paste
225g/8oz unsalted butter, at room temperature
1 free-range egg, lightly beaten