Sift the flour and the baking powder into a separate bowl. The flour should be sifted necessarily - so it is oxygenated, and the dough becomes airy. If you have time, it is even better to sift the flour twice. STEP 4: Continuing to beat the eggs, now on low speed, in batches add the sifted flour to the batter. If you beat at high speed, the dough may shrink a lot and lose its fluffiness, because the longer the eggs are beaten, the denser they become, and the more oxygen escapes from the mass....
