||Cream together butter and sugar.
||Add eggs, beating well.
||Add sour cream and vanilla.
||Fold in flour, baking powder and salt.
||Grease and flour a 9" x 13" pan. Pour ½ of batter into pan.
||Combine topping ingredients. Top batter with half of topping mix.
||Add rest of batter and top with remaining topping mix.
||Bake at 300° for 55 to 60 minutes. May take a bit longer, so be sure to test until toothpick comes out clean!