Sour Cream Coffee Cake

Butter a 9 x 13 inch baking dish or a 9 inch springform pan.Preheat oven to 350.In stand mixer or using hand mixer, cream 2 sticks of butter.Add 1 cup of granulated sugar and ½ cup of brown sugar. Mix well until creamy.Add 2 eggs and mix well.In a separate bowl, whisk together flour, baking powder, salt, baking soda, cinnamon and nutmeg.Add the flour mixture to the butter mixture alternately with sour cream. Mix until all is well blended.Stir in vanilla.Pour half the batter into a greased pan. You can use a 9 x 13 inch baking dish or a 9-inch springform pan. You could probably also use a 9 x 9 inch baking pan and just adjust the time. I prefer to use the 9 x 13 inch baking dish.To make the filling, stir together ½ cup of dark brown sugar and 2 teaspoons cinnamon and sprinkle over the first half of batter.Gently spread remaining batter over the filling, patting it out to the edges.For the streusel topping, stir together the sugars, flour and cinnamon. Don't try to get all the lumps out of the brown sugar, just the biggest ones. Stir in 7 tablespoons of melted butter just until the mixture is moistened and no flour is visible. Don't stir too much.Sprinkle the streusel over the batter.Bake at at 350° for 40-45 minutes, checking at about 30 minutes.If using a springform pan, bake at 325° for about an hour or until a tester in the center comes out clean.