Preheat oven to 350º. Butter a 9 x 13" pan.
Sift the dry ingredients together with a whisk and set aside.
Cream butter and sugar well. Add eggs, one at a time; beating well after each one. Fold in sour cream and vanilla.
Stir in dry ingredients.
Pour half of the batter into prepared pan.
Mix nuts, brown sugar and cinnamon together. Sprinkle 3/4 of the nut mixture onto batter. Top with the remainder of the batter. Sprinkle on the rest of the nut mixture. Bake for 45 - 60 minutes. Cool for 10 minutes before serving.
1 cup butter
2 cups sugar
1 cup sour cream
1 tsp vanilla
2 cups flour
1 tsp baking powder
1/4 tsp salt
1 cup brown sugar
1 cup chopped pecans (or walnuts)
2 tsp cinnamon