German Chocolate Crinkle Cookies

• 1 egg
• 1/2 instant mashed potato flakes
• 200 gr powdered sugar
• 170 gr butter
• 100 gr sugar
• 75 ml milk
• 65 gr nuts (chopped)
• 14 gr soft margarine
• 5 ml cream of tartar
• 4 gr unsweetened cocoa