1. Prepare the Crust:

1. Preheat your oven to 350°F (175°C) and grease a 10-inch bundt pan.
2. In a large mixing bowl, cream together the butter and sugar until light and fluffy. Add eggs one at a time, mixing well after each addition.
3. In another bowl, whisk together flour, baking soda, and salt. Gradually add to the creamed mixture alternately with sour cream, beginning and ending with flour mixture. Stir in vanilla.
4. In a small bowl, mix pecans, brown sugar, and cinnamon. Pour half of the cake batter into the pan, sprinkle with half the pecan mixture, top with remaining batter and sprinkle remaining pecan mixture on the batter.
5. Bake for 60-70 minutes or until a toothpick inserted in the center comes out clean. Cool in the pan for 15 minutes before inverting onto a wire rack to cool completely.