Delicious Mazurka

Description
In Romanian: Mazurca delicioasa

Ingredients

 * 14 oz / 400 g confectioner's sugar
 * 14 oz / 400 g butter
 * 2 cups blanched, peeled and finely chopped almonds
 * 1½ cups flour
 * 12 eggs
 * vanilla
 * butter to grease the pan

Directions

 * 1) Cream the butter, add the almonds and mix again.
 * 2) Add flour, then yolks, one by one, vanilla and sugar, little by little; mix very well.
 * 3) At the end, gradually add the whipped egg whites.
 * 4) Fold them in gently.
 * 5) Pour the batter into a baking pan covered with buttered paper and bake at medium heat.
 * 6) When cold, cut into medium sized squares.