Whisk together eggs, milk, sugar, and salt until smooth. Whisk in flour until incorporated, then set mixture aside and let stand for 30 minutes. Preheat oven to 500 degrees F (260 degrees C). Place butter into a 9x13 inch glass baking dish, and place into the preheated oven until it melts, then brush it all over the insides of the hot dish. Pour batter into hot baking dish and bake in preheated oven for 15 minutes. Sprinkle with lemon juice, top with berries, and dust with confectioner's sugar; serve immediately with whipped cream.