1. soften the butter at room temperature, add the powdered sugar and whip, stirring constantly, the whipped butter becomes lighter in color and creamy, and the sugar particles are basically invisible.

2. Beat the egg whites slightly and pour them into the butter in step 1, mixing well.

3. Sifted flour poured into step 2, stirring constantly and evenly into a batter

4. Go to a laminating tape, from the center to turn, into the batter in step 3, seal the mouth of the laminating bag, around the finger, baking sheet lined with greaseproof paper, extruded in the upper edge of the round can be.

5. Oven modulation 165 degrees, preheat for 10 minutes, put the baking tray, bake for about 20 minutes, until the edges slightly color can be.