Heat oven to 425°F. Spray a 12-cup muffin tin with nonstick cooking spray, or line with paper cups. In large bowl, whisk together oil and sugar. Add egg, milk and vanilla and whisk till smooth.
In small bowl, combine flours, baking powder, baking soda and salt. Stir in 3/4 cup blueberries, then fold this mixture into the wet ingredients. Do not over mix. Spoon batter into prepared pan, using about 1/4 cup batter for each muffin. Press remaining blueberries onto tops of muffins, pushing in slightly.
In small bowl, combine topping ingredients with fork or fingers. Sprinkle over muffin tops.
Place muffins in oven. Reduce heat to 350°F. Bake about 20 minutes, or till a wooden pick inserted in center of muffins returns with just a few crumbs. Cool in pans 5 minutes, then transfer to wire rack to finish cooling.