Mix in a small bowl and set aside:
1/2 cup of sugar
1/2 cup chopped walnuts
1 Tbsp cocoa
1 tsp cinnamon
Cream in a large bowl:
1/2 cup butter
1 cup sugar
3 eggs, one at a time, mixing well after each addition.
Mix in a small bowl:
3 cups flour
1 tbsp baking powder
1 tsp baking soda
Add to creamed mixture alternately with:
1 1/4 cups sour cream
(I start with 1 c. flour mixture, then add 1/2 the sour cream, then add another 1 c of flour mixture, then add the rest of the sour cream ending with the last of the flour mixture)
Pour 1/2 the batter into a greased and floured 9″ bundt pan or tube pan. Sprinkle the filling over this and carefully spoon the rest of the batter over this spreading till even/smooth on top.
Bake at 375C for 1 hour or until tester comes out clean. Loosen from sides and leave to cool before removing from pan.