04In one more bowl, whisk together the oil, sugar, egg and vanilla extract. Add the milk/lemon mixture and then add the wet ingredients to the dry ingredients. Mix until almost combined and then add the blueberries and finish stirring.
05Divide batter between the 12 muffin cups and bake for 18-20 minutes. Remove to cool on a wire rack.
06While muffins are cooling, prepare the topping. Mix together melted butter and lemon juice in a small bowl. In a separate bowl, add the sugar. Dip the slightly cooled muffins first into the butter mixture and then into the sugar to coat the top of the muffin. Allow the dipped muffins to cool completely on wire racks.