Vanilla custard bathes buttered brioche in this English-style bread pudding. For a rich but understated finish, drizzle cinnamon cream over top.
Position a rack in the center of the oven. Preheat oven to 375°. Butter a 2- to 2 1/2-quart baking dish.
In a small bowl, combine 6 tablespoons butter, 1 tablespoon sugar and 1/2 teaspoon cinnamon until creamy. Spread butter mixture evenly on bread slices. Press slices together to make three sandwiches. Cut sandwiches diagonally into quarters. Arrange quarters in prepared baking dish with corners pointing up slightly.
In a medium bowl, thoroughly whisk together half-and-half, eggs, 3 tablespoons sugar, 3/4 teaspoon cinnamon, the vanilla and salt. Slowly pour mixture over bread in dish. Using a large spoon, baste bread with free egg mixture; let stand 5 minutes.
In a small cup, stir together 1 1/2 teaspoons sugar and 1/4 teaspoon cinnamon. Sprinkle over the top.
Bake until puffed and golden and a knife inserted in the center comes out clean, about 35 minutes. Cool on a wire rack 30 minutes before serving. Serve warm or at room temperature.