Preheat your oven to 400 degrees. Grease two 12-cup muffin tins or line with paper liners.
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 at this point.
Toss the berries of your choice with the remaining ½ cup of flour. Gently fold the berries and flour into the batter.
Fill each paper-lined muffin cup ¾ full, and sprinkle generously with the remaining 2 tablespoons of sugar. Tip: try these parchment paper muffin liners!
Bake for 18-20 minutes, until a toothpick inserted into the center comes out clean.
Cool for at least 10 minutes before removing the muffins from the pan.