Preheat oven to 400*. Lightly grease 12 muffin cups or line with paper baking cups; set aside.
Mix flour, 2/3 cup sugar, baking powder, baking soda, and salt in a large bowl. Mix sour cream, milk, oil, egg, orange peel and vanilla in a medium bowl. Add to flour mixture; stir just till dry ingredients are moistened (batter will be thick and slightly lumpy). Gently stir in blueberries.
Spoon batter into prepared muffin cups, filling each cup 2/3 full. Mix 2 TBSP sugar and cinnamon. Sprinkle over muffins. Bake for 20-25 minutes or till toothpick inserted comes out clean.