Applesauce Cake/butter Frosting

• 1 butter frosting (white)
• 1 egg (very)
• 600 gr confectioners sugar
• 400 gr sugar
• 350 ml applesauce
• 350 gr sifted cake flour
• 120 ml water
• 95 gr soft shortening
• 65 gr shortening
• 60 gr walnuts