These are the excellent blueberry muffins that Mom always makes, including the crumb topping.
Beat eggs until light colored; add milk and oil. Quickly stir milk mixture into dry ingredients. Fold in blueberries. Fill paper-lined muffin tins 1/2 to 2/3rds full. In a separate bowl, combine topping ingredients with fork, until crumbly. Top each muffin with topping. Bake muffins at 350 degrees for 15-20 minutes. Remove from muffin tins and cool slightly.
Makes 15 muffins.