Heat oven to 350. Spray a 9" x 13" baking dish w/ cooking spray. Measure out 2 tsp dry cake mix into small bowl, set aside. Place remaining cake mix into lg bowl.
Add sour cream, oil, water and eggs. Beat until mixed. Beat 2 more mins on medium. Pour batter into pan. Drizzle honey over batter. In small bowl, combine brown sugar, cinnamon and pecans. Sprinkle over batter, swirl batter w/ a knife.
Place blueberries in reserved cake mix bowl. Toss to coat. Sprinkle berries over batter. Bake 40-45 mins. Let cool. In bowl, whisk together powdered sugar, milk and vanilla until smooth. Spoon glaze over warm cake.