1. Preheat oven to 400 degrees. In oven, melt butter in a 9-inch pie plate, about 6 minutes.
2. In a blender, combine milk, eggs, 1/2 cup sugar, flour, salt, and vanilla. Add melted butter and blend mixture until smooth, 30 seconds.
3. Distribute berries evenly in pie plate and pour batter over top. Sprinkle with 1 tablespoon sugar and bake until slightly puffed and just set in middle, 20 to 25 minutes. Heat broiler and broil until top is deep golden brown, 2 to 3 minutes. Serve warm.