Sour Cream Coffee Cake III

Preheat oven to 350 degrees F (175 degrees C).

Grease a 9x13 inch baking 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 batter in the prepared pan.

Prepare the filling: In a medium bowl mix 1/3 cup flour, brown sugar, 2 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 to 40 minutes in the preheated oven, or until a toothpick inserted near the center comes out clean.