*****Alternate sour cream and flour when mixing together. Batter will be super thick.*****
Mix filling and topping ingredients in a small bowl and set aside.
Cream together the butter and sugar. Add eggs one at a time, mixing well after adding each one. Next, add vanilla.
Add flour, baking soda, baking powder and salt and remember to alternate with sour cream/flour. The mixture will be thick and it's okay.
Put half of batter in a greased 13X9 baking dish and sprinkle half of filling and topping mix on top of batter. Put the rest of the batter on top and put remaining filling and topping mix on top of cake.
Bake at 350* for about 45 minutes or until a toothpick comes out clean.