Cake with nuts

INGREDIENTS
- 300gr butter
- 300gr sugar
- 6 egg yolks
- 6 egg whites
- 100gr grinded nuts
- 150gr Farino flour  

INSTRUCTIONS
Start mixing the butter and the sugar. Add one by one the egg yolks and work them until you get a foamy mass. Add the flour and the grinded nuts. Marengue the egg whites separately and blend them with the previous made mixture.
Pour te mixture in a 22cmm-diameter, round pan, that has been buttered and sprinkled with flour. Bake it in a preheated oven of 160-170 Celcius degrees for about 20-30 minutes. Take it out of the oven and let it chill. Finally sprinkle it with powder sugar.