Heat oven to 350 degrees. Lightly butter a medium-size flameproof baking dish at least 1 1/2 inches deep.

Place the milk, 1/3 cup granulated sugar, eggs, vanilla, salt and flour in a blender. Blend at top speed until smooth and frothy, about 1 minute.

Pour a 1/4-inch layer of batter in the baking dish. Turn on a stove burner to low and set dish on top for a minute or two, until a film of batter has set in the bottom of the dish. Remove from heat.

Spread berries over the batter and sprinkle on the remaining 1/3 cup granulated sugar. Pour on the rest of the batter and smooth with the back of a spoon. Place in the center of the oven and bake about 50 minutes, until top is puffed and browned and a tester plunged into its center comes out clean.