"Streusel Coffee Cake"
1/2 cup butter, at room temperature
3/4 cups sugar
3 eggs, at room temperature
1 1/2 cups flour
1 tsp baking soda
1 tsp baking powder
1 cup sour cream
(Topping)
1 cup brown sugar
2 teaspoons cinnamon
1 cup walnuts, finely chopped
6 tablespoons cold butter
Preheat oven to 350 F. Line the bottom of a 9-inch square pan with wax paper and grease thoroughly. For the topping, place ingredients in a bowl and mix with a fork or your fingertips, until the mix resembles coarse crumbs (streusel).
For the cake, cream the butter with electric mixer until soft. Add the sugar. Continue beating until mixture is light and fluffy. Add the eggs, one at a time, until mixed well. In another bowl, mix the flour and other dry ingredients. Fold the flour into the butter mixture in 3 batches, alternating with the sour cream. Pour half of the mixture in the prepared pan and sprinkle half of the brown sugar topping mix over batter. Pour the remaining batter in pan and top with the remaining sugar mixture. Bake until browned, 60-70 minutes.
