Preheat oven to 350 degrees F (175 degrees C). Lightly grease an 8x8 inch baking dish.
Arrange the blueberries over the bottom of the prepared baking dish. Whisk together the eggs and egg yolk until light and fluffy. Stir in the sugar, and continue whisking until mixture thickens. Whisk in the milk, vanilla extract, sifted flour, and salt, one at a time, until mixture is light and airy. Pour the mixture over the berries to cover evenly.
Bake on center rack in preheated oven until top is golden and springs back when touched, about 45 minutes. Cool slightly, and cut into 8 equal pieces. Dust with confectioners' sugar, and serve immediately.
