Tangy Lemon Streusel Cake
["1 pkg. Betty Crocker SuperMoist lemon cake mix", "1 (8 oz.) container plain yogurt", "1/3 c. vegetable oil", "1/4 c. water", "3 eggs", "1 c. finely chopped walnuts", "1/3 c. brown sugar", "1 tsp. cinnamon"]
["Heat oven to 325\u00b0.", "Grease and flour a 13 x 9 x 2-inch pan. Reserve 2 tablespoons of dry cake mix.", "Beat remaining cake mix, yogurt, oil, water and eggs in large bowl on low speed for 30 seconds.", "Beat on medium speed for 2 minutes."]
["lemon cake", "yogurt", "vegetable oil", "water", "eggs", "walnuts", "brown sugar", "cinnamon"]