Sour Cream Coffee Cake

1 cup butter
2 cups sugar
2 eggs
1 cup sour cream
1/2 teaspoon vanilla
2 cups flour
1 teaspoon baking powder
1/2 teaspoon salt
2/3 cup flour
1 cup packed brown sugar
4 tablespoons melted butter
2 teaspoons ground cinnamon

Preheat oven to 350. Grease a 13x9 inch pan. In a large bowl, cream together 1 cup butter and white sugar until light and fluffy. Beat in the eggs one at a time, then stir in the sour cream and vanilla. Mix in 2 cups flour, baking powder and salt. Spread 1/2 of the batter in the prepared pan.

Prepare the filling: in a medium bowl, mix 2/3 cup flour, brown sugar, 4 tablespoons melted butter and cinnamon. Sprinkle cake batter with 1/2 the filling. Spread second half of batter over the filling, and top with remaining filling.

Bake 35-40 minutes in oven until a toothpick inserted near the center comes out clean.

Recipe modified slightly from AllRecipes.com