In a medium sized bowl, combine the walnuts, mini chocolate chips, sugar and cinnamon together.

Set aside while you prepare the cake batter.

In a large bowl using an electric mixer or your Kitchen Aid mixer, cream together the 2 sticks butter and 1 cup sugar until light and fluffy.

Add in the eggs, one at a time and beat until smooth.

Add the sour cream and then the vanilla.

Mix until everything is combined.

In another bowl, combine the flour, baking powder and baking soda.

Slowly add the dry ingredients to the bowl of the wet ingredients.

Mix until just combined and set aside while you prepare the streusel topping.

Pour half of the batter into the bottom of your prepared 9 inch spring form pan or traditional cake tube pan and spread it around to cover the bottom of the pan. 

Sprinkle half of the streusel topping over the first layer of batter.

Carefully spread the remaining batter over the layer of streusel topping.

Sprinkle the remaining streusel topping over the top.

Bake in a preheated 350 degree oven for 45 to 60 minutes or until toothpick inserted in the center comes out clean.