Preheat your oven to 375°F. Line a 12 count muffin tin with paper cups, and set aside.
In a large bowl, combiner your sugar, milk, oil, eggs, and vanilla extract. Whisk to combine.
Add the flour, baking powder, cornstarch, and salt to the wet ingredients. Mix together until just incorporated. Take care not to over mix or the muffins can end up dense! Gently fold in your blueberries.
Using 2 spoons or a large ice cream scoop, portion out the batter into 12, standard sized muffin tins. Bake in a preheated 375°F oven for 20 to 25 minutes, or until golden brown on top and a skewer inserted into the center comes out clean of any batter. Cool slightly before serving.