Place flour, cornmeal, baking powder and salt in a bowl.
In a stand mixer with the paddle attachment, add the butter, and whip until soft. Add the sugar and whip on medium speed until fully incorporated, about 2 minutes. Add the vanilla and incorporate. While on medium speed, add the eggs one at a time, completely combining in between each egg. Add 1/3 of the dry ingredients, then 1/2 of the sour cream, then another 1/3 of the dry ingredients, then the sour cream, then the last of the dry ingredients. Place in a buttered and floured loaf pan (9 x 5 x 3) and bake in a 350º F over for 50 to 55 minutes, or until a cake tester comes out clean. Cool for 10 minutes on a Calphalon Classic Nonstick Bakeware rack and then remove from pan (Run a knife around the edges to release if necessary.). Cool completely.
Serve with Chef Peter Max Rubin's Chevre Ice Cream and Blackberry and Honey Coulis for the perfect late summer dinner dessert!