1. Preheat oven to 400 degrees F (200 degrees C). Grease 24 muffin cups or line with paper muffin liners. In large bowl beat eggs, gradually add sugar while beating. Continue beating while slowly pouring in oil. Stir in vanilla. In a separate bowl, stir together flour, salt and baking soda. Stir dry ingredients into egg mixture alternately with sour cream. Gently fold in blueberries.
2. Scoop batter into prepared muffin cups. In a small bowl, mix together 2 tablespoons flour, brown sugar and cinnamon. Cut in butter until mixture resembles coarse crumbs. Sprinkle topping over unbaked muffins.