Step 1

Beat butter, margarine and sugar (1 1/2 cups) until creamy.

Step 2

Add the eggs, one at a time, and continue beating.

Step 3

In a separate bowl, stir together flour, baking powder, and baking soda. Add to the creamed mixture alternately with sour cream, mixing after each addition.

Step 4

Add vanilla, and mix until completely incorporated.

Step 5

In a small bowl, mix chopped nuts, sugar (4 T.) and cinnamon.

Step 6

Prepare a Bundt pan by greasing generously, and lightly dusting with flour.

Step 7

Pour 1/3 of the batter into the bottom of the prepared Bundt pan. Smooth into a consistent layer with a knife. Sprinkle with 1/2 of the cinnamon sugar mixture.

Step 8

Pour an additional 1/3 of the batter over the cinnamon sugar layer, smooth again with a knife.  Sprinkle with the remaining 1/2 of the cinnamon sugar mixture.

Step 9

Spread the remaining 1/3 batter on top the cinnamon sugar layer, and smooth with a knife.

Step 10

Bake in a preheated 350 degree F oven for 1 hour.

Step 11

Remove from the oven, and let cool for 1 hour in the pan.