Cream together butter, sugar, and eggs.
Add sour cream, vanilla, and apples.
Sift together dry ingredients, add to wet mixture.
Spread 1/2 batter in a greased 9 x 13 pan.
Sprinkle with 1/2 sugar mixture.
Spread remaining batter on top and top with the rest of the sugar mixture.
Bake at 350°F for 45-50 minutes.