Mix together the oil and the sugar. Add the eggs 1 at a time, beating after each addition. Sift together the flour, baking powder, cinnamon, nutmeg, salt and ground ginger. Add the dry ingredients to the wet ingredients. Fold in the apples and the walnuts. Bake in 2 (9-inch) greased and floured cake pans for 1 hour in a preheated 350 degree oven or until center is done. Garnish with confectioners' sugar and whipped cream.