Preheat your oven to 400°F (200°C) and line a 12-cup muffin pan with paper liners to prevent sticking and ensure easy removal after baking.
In a medium bowl, whisk together the all-purpose flour, baking powder, and salt until well combined. This helps distribute the leavening evenly for a consistent rise.
In a small bowl, add the blueberries and toss them gently with about a tablespoon of the dry flour mixture. This step helps keep the blueberries from sinking to the bottom of the muffins while baking.
In a large mixing bowl, beat together the granulated sugar, melted butter, and eggs on medium speed until the mixture becomes light, smooth, and slightly fluffy (about 2 minutes). Then mix in the vanilla extract for added flavor.
Gradually add the dry ingredients into the wet mixture in three parts, alternating with the milk. Mix gently after each addition until just combined. Avoid overmixing, as this can make the muffins dense instead of soft and fluffy.
Carefully fold in the coated blueberries using a spatula, making sure not to break them. This keeps the muffins light while evenly distributing the berries.
Divide the batter evenly among the muffin cups, filling each almost to the top for a tall, bakery-style muffin.
Sprinkle a few extra blueberries on top and add coarse sugar if desired for a slightly crunchy, sweet topping.
Bake in the preheated oven for about 20 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out with a few moist crumbs.
Remove the muffins from the oven and let them cool in the pan for a few minutes. Then transfer them to a wire rack to cool completely before serving.