Sour Cream Banana Cake

1⁄2 cup unsalted butter, softened
1 cup sugar
2 eggs
1 cup banana, mashed
1⁄2 teaspoon vanilla extract
1⁄2 cup sour cream
2 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1⁄4 teaspoon salt 

1⁄2 cup walnuts, finely chopped

1⁄4 cups sugar (2T sugar, 2T brown sugar) 

1⁄2 teaspoon cinnamon
1⁄4 cup powdered sugar

 

DIRECTIONS
Preheat oven to 350°F 
Combine butter and 1 cup sugar in a bowl and beat with an electric mixer until light and fluffy. 
Add eggs one at a time, mixing thoroughly after each addition. 
Stir in bananas, vanilla and sour cream.
Sift flour and next 3 ingredients together in a bowl. 
Fold into butter mixture until just blended.
Combine nuts, cinnamon and remaining granulated sugar in another bowl. 
Sprinkle half of nut mixture into a buttered and floured tube or bundt pan. (I used all of it in the middle) 
Add half the batter. Sprinkle with remaining nut mixture and cover with remaining batter.
Bake 45-50 minutes until a tester comes out clean when inserted in center. 
Invert pan and cool. 
Sprinkle with powdered sugar before serving.

Recipe is from food.com