Grease a 6cm deep, 14cm x 24cm (7-cup capacity) baking dish. Cut each brioche slice in half cross ways and arrange standing upright in dish.
Whisk eggs, 1/2 cup sugar and vanilla in a jug until well combined. Add milk and cream and whisk to combine. Pour milk mixture over brioche. Set aside for 30 minutes or until brioche has absorbed about two-thirds of milk mixture.
Preheat oven to 160°C. Arrange cherries over brioche. Place dish on a baking tray and bake pudding for 40 to 45 minutes or until centre is just set and top is puffed.
Meanwhile, place remaining 3/4 cup sugar in a small, non-stick frying pan over medium heat. Gently tilt pan back and forth until sugar dissolves and turns to toffee. Remove from heat. Drizzle toffee over pudding and allow to set. Serve pudding warm with cream and custard if desired.