Cinnamon Crumb Coffee Cake
1 cup brown sugar
2 1/2 teaspoons ground cinnamon
4 tablespoons cold butter
2/3 cup chopped walnuts
1/2 cup butter, room temperature
1/4 cup sugar
2 cups flour
1 teaspoon baking soda
1 teaspoon baking powder
1 cup sour cream
Line the bottom of a 9-inch square pan with wax paper. Spray paper and sides with cooking spray. Preheat oven to 350.
In a small bowl, prepare the crumb filling and topping by mixing together the brown sugar and cinnamon. Cut 4 tablespoons of cold butter into small pieces and then mix into sugar and cinnamon using a pastry blender. Add the walnuts. Set aside.
In a large mixer bowl, cream the butter and sugar until light and fluffy. Add the eggs, beating well after each addition.
In a medium bowl, mix together the flour, baking soda, and baking powder. Alternate adding flour mixture and sour cream to the butter, eggs, and sugar.
Pour half of butter into prepared pan. Sprinkle with cinnamon and sugar mixture. Top with remaining batter and then remaining cinnamon and sugar mixture.
Bake 50-60 minutes. Let stand in pan for 5 minutes before removing from pan.