CINNAMON SOUR CREAM COFFEE CAKE
Vegetable oil spray for misting the pan
All-purpose flour for dusting the pan
1 package (18.5 ounces) plain butter recipe yellow cake mix
1/4 cup all-purpose flour
1/2 cup packed light brown sugar
2 teaspoons cinnamon
1/2 cup finely chopped pecans, if desired
1 cup sour cream
4 large eggs
1/3 cup vegetable oil
1/4 cup water
1 teaspoon pure vanilla extract
Place a rack in the center of the oven, and preheat the oven to 350 degrees. Lightly mist a 10-inch tube pan with the vegetable oil spray, and dust with flour. Shake out the excess flour and set the pan aside.
Place the cake mix and flour in a large mixing bowl and stir to combine. Measure out 2 tablespoons of this mixture and place it in a small bowl. Add the sugar, cinnamon, and pecans, if desired, to the small bowl and stir to combine. Set this aside.
Add the sour cream, eggs, oil, water, and vanilla to the large mixing bowl with the cake mix and flour. Blend with an electric mixer on low speed until the ingredients are incorporated. Stop the machine, and scrape down the sides of the bowl with a rubber spatula. Increase the speed to medium and blend 1 1/2 to 2 minutes more, or until the mixture is well combined and has lightened in texture. Spoon half of the batter into the prepared pan. With your fingers scatter all but 2 tablespoons of the sugar and cinnamon filling on top of the batter. Spoon the remaining batter into the pan, and carefully spread it out so as not to disturb the sugar layer. Sprinkle the remaining filling on top of the batter, and place the pan in the oven.
Bake the cake until it springs back when lightly pressed and the top has lightly browned, 52 to 55 minutes. Remove the pan from the oven, and place on a rack to cool for 20 minutes. Run a knife around the edges of the pan, and invert the cake once, then again so that the cake rests right-side up on the cooling rack. Let it cool for 30 minutes, then slice and serve.