Grease well a 13 x 9 inch baking dish. Cut brad into 18 (1 inch) slices. Arrange slices in one layer in bottom of pan. Beat eggs, milk, sugar, salt, and vanilla in a large bowl. When thoroughly mixed, pour over bread in pan. Bread will float on top of liquid.
Cut each pat of butter into 4 pieces. Dot each piece of bread with piece of butter. Sprinkle with cinnamon. Cover; refrigerate overnight, or up to 36 hours.
Place dish, uncovered, in cold oven. Turn oven temperature to 350 degrees (325 degrees if glass) and bake 45-50 minutes or until bread is puffy and light brown. Remove from oven; allow to set 5 minutes. Bread will rise to top with custard on bottom of dish. Serve with raspberry, strawberry, or coconut syrups. Yields 9 servings.
