TOPPING:

1/2 c. chopped nuts
1/2 c. sugar
1/2 c. chocolate chips
1 tsp. cinnamon

In food processor, chop chips and nuts with 3 or 4 on/off turns. Add cinnamon, sugar and whirl until combined. Set aside.

CAKE:

2 tsp. baking powder
1 tsp. baking soda
pinch salt
2 1/2 c. sifted flour
1 c. sour cream
1 tsp. vanilla
1 tsp. lemon juice
3 eggs
1 c. sugar
1/2 c. butter, cut in 4 pieces
1/2 c. margarine, cut in 4 pieces

Insert steel blade. Place butter and margarine in work bowl of food processor. Pour sugar over and process until creamed. Continue processing and add eggs, one at a time through feed. Add vanilla and lemon juice. Sift dry ingredients, add alternating with sour cream, whirling only until combined each time. DO NOT OVER PROCESS. Pour 1/2 batter into greased 10-inch tube pan. Sprinkle with 1/2 topping. Pour remaining batter and top with topping.

Bake at 350°F for 35 to 45 minutes.