Ingredients 

• 1 cup sugar
• 5 egg yolks
• Juice of 1orange
• 1 cup All purpose flour
• 3 1/2 teaspoons baking powder 

• In a large bowl mix all the above ingredients. 
• Fold in 5 egg whites (beaten stiff). 
• Pour cake mixture into a buttered cake pan. Bake at 375 degrees for 10 minutes. Lower oven heat to 350 degrees and bake for another 30 minutes. Remove the cake from oven and cool. 
• When cake has cooled, remove from pan to a cake plate.Cut the cake into diamond shape pieces.