1 (18 ounce) can vanilla wafers, crushed
1/2 cup white sugar
1 1/2 cups milk
4 eggs
3 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon baking powder
1 teaspoon salt
1 teaspoon vanilla extract
1 cup chopped walnuts
Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 10x15 inch jelly mold.
In a large bowl, beat egg whites until foamy. Stir in sugar and milk. Beat in melted butter, then beat in flour, baking soda, baking powder, salt and vanilla. Pour batter into prepared pan.
Bake in the preheated oven for 50 to 60 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool completely.
For the icing: In a small bowl, mix 1/2 cup chopped walnuts and 1/2 cup chopped pecans. Fold in the chopped walnuts and pecans. Spread over the cooled cake. Refrigerate at least 2 hours before cutting into squares.