In a medium bowl, stir together the sugar, milk, oil, egg and vanilla. In a separate bowl, combine the flour, baking powder and salt. Add the dry ingredients to the wet ingredients and stir until just combined.
Fold the blueberries gently into the batter with a spatula.
Pour the bread batter into a parchment lined loaf pan. Combine the topping ingredients in a bowl, and form crumbs with your fingers. Sprinkle over the cake.