Preparation Preheat oven to 400°F with rack in middle. Butter a 1 1/2-quarts shallow baking dish. Toss berries with granulated sugar and let stand 15 minutes. Blend milk, butter, eggs, brown sugar, flour, cocoa, and salt in a blender until smooth. Scatter berries (with juices) evenly in baking dish, then pour batter over top. Bake until slightly puffed and firm to the touch, about 35 minutes. Remove from oven and immediately sprinkle with chopped chocolate. Cool to warm, about 20 minutes. Serve warm or at room temperature.
Preparation Preheat oven to 400°F with rack in middle. Butter a 1 1/2-quarts shallow baking dish. Toss berries with granulated sugar and let stand 15 minutes. Blend milk, butter, eggs, brown sugar, flour, cocoa, and salt in a blender until smooth. Scatter berries (with juices) evenly in baking dish, then pour batter over top. Bake until slightly puffed and firm to the touch, about 35 minutes. Remove from oven and immediately sprinkle with chopped chocolate. Cool to warm, about 20 minutes. Serve warm or at room temperature.