1. Mix low-gluten flour and baking powder and sieve. Take a large clean bowl, egg yolk. Pour the eggs into a large bowl and beat with a whisk. Add fine sugar in three times during the process of beating (the bowl and the beating head should be clean, oil-free and water-free)
2. After being beaten, the volume of the egg liquid will expand several times. When the egg beating head is lifted, the dripping egg liquid will not disappear immediately, and lines can be drawn on the surface of the egg liquid in the bowl, which means that it has been beaten. Pour the sifted low-gluten flour and baking powder mixture into the beaten egg
3. Use a rubber spatula to mix the flour and egg mixture evenly from the bottom up, do not stir in circular motions. The mixing action should be rapid and larger, so that the flour and egg liquid will be mixed as quickly as possible into a batter. If it takes too long or stirs in a circular motion, it will cause the whipped egg liquid to defoam. The mixed batter should be smooth and puffy.
4. Put the batter into the piping bag, cut a small round hole at the tip of the piping bag, and squeeze out a small round batter with a diameter of about 2cm on the baking pan covered with parchment paper. Put the baking pan into the preheated oven with the upper and lower fire at 170℃, the middle and upper layer, bake for about 15 minutes, until the surface is golden brown
