Preheat the oven to 400°F. Lightly grease the cups of a standard muffin pan (12 muffins); or line with paper baking cups, and grease the paper cups., Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. , Whisk together the flour, brown sugar, salt, baking powder, baking soda, and cinnamon. Stir in the blueberries last., In a separate bowl, whisk together the vanilla, vegetable oil, and buttermilk or yogurt., Pour the liquid ingredients into the dry ingredients, stirring just to combine., Spoon the batter into the prepared muffin cups, filling them full. A slightly heaped muffin scoop of batter is the right amount., Sprinkle the tops of the muffins with coarse sparkling sugar or cinnamon sugar, if desired., Bake the muffins for 18 to 20 minutes, until a toothpick inserted into the middle of one of the center muffins comes out clean., Remove the muffins from the oven, and after 5 minutes (or when they're cool enough to handle) transfer them to a rack to cool. Serve warm, or at room temperature. Store leftovers loosely wrapped at room temperature for several days; freeze for longer storage.