Chocolate chunk coffee cake

Ingredients:
1.Butter 1 cup
2.Sugar 1 cup
3.Eggs 3
4.Sour cream 1 cup
5.Vanilla essence 2 tsp
6.Maida flour 2 cups
7.Baking powder 1 tsp
8.Baking soda 1 tsp
9.salt 1/2 tsp

Topping:
a.semi-sweet chocolate chopped 3 cups
b.chopped walnuts 1 cup
c.sugar 1 cup

Method:
1.Take a small bowl.Combine all topping ingredients.
Set aside.Beat butter and sugar in a large bowl.
2.Beat in eggs,sour cream and vanilla until well mixed.
Mix maida flour,baking soda,baking powder and salt in bowl.
Add flour mixture into batter,beating until smooth.
Sprinkle one third of the topping.
Repeat layering two more times.
3.Bake 55 to60 minutes in medium high.