Preheat oven to 375 degrees. Grease and flour a 10-inch tube pan. For streusel filling combine 2 tablespoon cake mix, brown sugar, and cinnamon in medium bowl, stir in pecans. For cake, combine remaining cake mix, flour, eggs, sour cream, oil, water, and sugar in a bowl. Beat at medium speed with electric mixer for 2 minutes. Pour two-thirds of batter into pan, sprinkle streusel filling.
Spoon remaining batter over filling. Bake for 45 to 55 minutes or until toothpick inserted in center comes out clean. Cool in pan 25 minutes, and invert onto a serving plate, and then cool completely. For glaze combine confectioners' sugar and milk in a small bowl. Stir until smooth, and then drizzle onto cake.