Sour Cream Chocolate Chunk Coffee Cake

I am a sucker when it comes to Sour Cream Coffee Cake, so I was thrilled to find this recipe for Sour Cream Chocolate Chunk Coffee Cake on the Scharffen Berger website. I know I've posted other Sour Cream Coffee Cake recipes, but I love this one, especially for the Chocolate Streusel Topping! I use a Bundt Pan, so it looks great, too! You can always use whatever chocolate you like, but since the recipe is from Scharffen Berger, I list it as the chocolate.

SOUR CREAM CHOCOLATE CHUNK COFFEE CAKE

Ingredients 

For Batter 
16 Tbsp unsalted butter
1-1/2 cups sugar
3 eggs
2 cups all purpose flour
1 tsp baking powder
1 tsp baking soda
1/4 tsp salt
1 cup sour cream
1 tsp vanilla
5 ounces SCHARFFEN BERGER 62% Cacao Semisweet Chocolate, chopped into 1/4-inch bits, or a scant cup of SCHRAFFEN BERGER 62% Cacao Semisweet Chocolate Baking Chunks

For Streusel Topping 
 2 ounces SCHARFFEN BERGER 62% Cacao Semisweet Chocolate
1/2 cup brown sugar
1/4 cup granulated sugar
1 teaspoon cinnamon
1 cup toasted walnuts, chopped

Directions
Preheat oven to 350 degrees F.
Grease Bundt pan generously and dust with flour. Beat butter and sugar until light and fluffy in electric mixer (using paddle attachment if using electric mixer). Add eggs, one at a time. Add vanilla extract.
Sift flour, baking soda, baking powder and salt. Gradually add flour mixture alternately with sour cream. Fold in chocolate pieces. Set aside.

To Make Streusel 
Melt 2 ounces of chocolate in top of double boiler or in bowl placed over pan of simmering water, stirring frequently until melted. Remove bowl from heat and mix in toasted walnuts until coated. Mix in sugars and cinnamon.

Pour half batter into prepared pan. Top with half streusel mixture. Cover with remaining batter and top with the remaining streusel mixture.
Bake for 1 hour or until a toothpick inserted in the center comes out dry.
Cool on a cake rack.
Unmold and serve warm or at room temperature.