How to Make It
Preheat the oven to 400°. Lightly brush a 9-inch square baking dish with butter. In a medium bowl, whisk the flour with the sugar and salt. In a blender, combine the half-and-half with the eggs, melted butter, vanilla bean seeds and liqueur. Pulse to combine. Add the dry ingredients and pulse until smooth.
Arrange the blackberries in a single layer in the baking dish. Pour the batter over the berries. Bake for about 25 minutes, until the clafoutis is set and golden. Transfer the dish to a wire rack and let cool for at least 15 minutes. Just before serving, dust the clafoutis with confectioners’ sugar and serve warm or at room temperature.