In a large bowl, combine the first five ingredients. In another bowl, combine the eggs, sour cream, yogurt, butter and vanilla. Stir into dry ingredients just until moistened.
In a small bowl, combine the streusel ingredients. Spoon half of batter into a 13-in. x 9-in. baking pan coated with cooking spray; sprinkle with half of streusel. Top with remaining batter and streusel. Bake at 350° for 30-35 minutes or until a toothpick inserted near the center comes out clean. Place pan on a wire rack to cool. Yield: 20 servings.