Beat together first 5 ingredients until blended. Beat in the next 3 ingredients until blended. Place batter in a lightly oiled 25 cm springform pan and place apples decoratively on top. Sprinkle top with cinnamon sugar.
Bake at 180ºC or about 35 to 40 minutes, or until a cake tester inserted in center, comes out clean. Allow to cool in pan.
When cool, remove from pan and sprinkle with 1 teaspoon sifted powdered sugar.
Serves 12.