Heat oven to 375° F convection or 400 degree conventional

Line a 12-cup muffin tin with paper liners.

In a medium bowl, combine 1 1/2 cups of the flour, 1/2 cup of the sugar, the baking powder, and salt.

Add the melted butter and combine.

In a second bowl, whisk together the buttermilk, egg, and vanilla. Gradually add the buttermilk mixture to the flour mixture and stir until just combined; the batter will be lumpy.

Toss the berries with the ¼ cup of flour in a bowl.

Carefully fold the berry mixture into the batter.

Fill each muffin cup 80% full. Sprinkle the batter with the brown sugar.

Bake for 10-15 minutes in a convention oven add about five minutes for a conventional oven or until a toothpick inserted into the center of a muffin comes out clean.

Serve warm.