Whisk together 3 ½ cups of flour, 1 cup of sugar, baking powder and salt in a large bowl. Stir in melted butter. The batter will be very crumbly at this point.

In a separate bowl, whisk together buttermilk, eggs and vanilla extract. Slowly add this mixture a little at a time to the butter mixture and stir until combined. The batter will still be slightly lumpy and possibly still have streaks of flour in it.

Toss the blueberries with the remaining ½ cup of flour. Gently fold the berries and flour into the batter. Refrigerate the batter for at least one hour.

Preheat your oven to 425°F. Grease two 12-cup muffin tins or line with paper liners. Tip: try these parchment paper muffin liners!

Fill each paper-lined muffin cup to the top. If you have empty cups, fill them with about ½" of water. Sprinkle a half teaspoon of sugar on top of the batter in each cup.

Bake at 425°F for about 6 minutes or until the muffins have risen about ½" above the rim of the muffin tin. Then turn the oven down to 400°F and bake for an additional 8-10 minutes, or until a toothpick inserted in the center comes out clean.

Cool the muffins in the pan for about 4 minutes and then transfer to a cooling rack to cool completely.