面团材料 Dough recipe 低筋面粉cake flour:280g 牛奶milk:120g 无盐黄油 unsaltedbutter:120g 盐salt:2g 糖sugar:20g 泡打粉baking powder:6g 蓝莓酱blueberry jam: 100g 牛奶蛋黄液Milk and egg yolk:30g 预热烤箱上下层190摄氏度烤18分钟 Preheat the upper and lower layers of the oven at 190 degrees Celsius and bake for 18 minutes