甜甜圈蛋糕 | Donut cake 蛋黄 Egg yolk 3 牛奶 Milk 25ml 无盐黄油 Unsalted butter 25g 低筋面粉 Cake flour 80g 蛋白 Egg white 3pcs 细砂糖 Caster sugar 80g 柠檬汁 lemon juice 烤箱预热 140℃ 25分钟;然后180℃ 10分钟 Bake in a preheated 140°C oven for 25 minutes; then 180°C for 10 minutes