Cheap Home Made Blueberry Muffins

Ingredients
1 ½ cups all-purpose flour

¾ cup granulated sugar

½ tsp salt

2 tsp baking powder

⅓ cup vegetable oil

1 large egg

½ cup milk

1 tsp vanilla extract

1 cup fresh or frozen blueberries

2 tbsp flour (to coat blueberries)

Optional: coarse sugar for topping