1Heat oven to 400°F. Grease bottoms only of 12 regular-size muffin cups or line with paper baking cups. In medium bowl, mix 1/4 cup flour, the brown sugar and cinnamon. Cut in butter, using pastry blender (or pulling 2 table knives through ingredients in opposite directions), until crumbly.
2In large bowl, beat milk, oil, vanilla and egg until well blended. Stir in 2 cups flour, the granulated sugar, baking powder and salt all at once just until flour is moistened (batter will be lumpy). Gently stir in blueberries. Divide batter evenly among muffin cups. Sprinkle each with about 2 teaspoons streusel topping.
3Bake 20 to 25 minutes or until golden brown. Immediately remove from pan to cooling rack. Serve warm or cool.