For Topping: Combine ingredients in small bowl and set aside.
For Cake: Preheat oven to 350 degrees. Butter or coat with nonstick spray a 9 x 13 inch baking pan. In a bowl, combine flour, baking soda and salt. Cream butter with sugar until light and fluffy. Beat in eggs, one at a time followed by sour cream and vanilla. Mix in dry ingredients until just blended. Spoon half the mixture into the baking pan and sprinkle half the topping over the batter. Top with remaining batter then topping. Bake for 45 to 50 minutes. Cool and cut. The aroma is fantastic!