Preheat oven to 400°. In a large bowl, combine the flour, sugar, baking powder, baking soda and salt; add berries and toss gently. In another bowl, combine the eggs, sour cream, oil and vanilla. Stir into dry ingredients just until moistened., Fill greased muffin cups two-thirds full. Bake until a toothpick inserted in the center comes out clean, 18-22 minutes. Cool for 5 minutes before removing from pan to a wire rack. Serve warm., Berry Cream Lemon Muffins: Prepare muffin recipe as directed, except substitute 1 cup lemon yogurt for the sour cream and add 2 teaspoon grated lemon peel with the vanilla., Berry Streusel Muffins: Prepare muffin recipe as directed. For topping, combine 3 tablespoons each all-purpose flour and quick-cooking oats, 2 tablespoons sugar and 1/8 teaspoon ground cinnamon. Cut in 2 tablespoons cold butter until crumbly. Sprinkle over muffins before baking.