Cake: Mix sugar, oil, eggs and vanilla. Set aside. Sift together the next 6 (dry) ingredients. Add to first mixture. Add apples and pecans. Bake in 9x13 pan at 350 degrees for 50-60 minutes (until cake pulls away from pan). Topping: Mix 1 stick butter, 1/2 cup brown sugar and 1/4 cup milk. Bring all to a boil. Pour over cake. Topping will kep in refrigerator for several weeks.