1. The butter is softened at room temperature, add icing sugar and stir evenly with a whisk (no need to beat)
2. Add the egg whites in three times, stir well each time, and then continue to add the next time
3. Stir until it is fluid and fine paste
4. Sift the flour and pour it into the protein paste and mix well (remember not to over-mix)
5. Put the mixed batter into a piping bag, and squeeze it out on a baking pan coated with grease or greased paper
6. Put it in the preheated Beo oven, 160 degrees, and bake the upper layer for 15 minutes until the edges are golden.
Tips:There will be a little difference in the temperature control and time between different styles of ovens, please pay attention
