Reserve 1 teaspoon chopped brownie crumbs. Place remaining chopped brownies in a bowl. Sprinkle with orange rind and juice. Stir gently.
Divide half the brownie mixture between four 250ml capacity glass jars or serving glasses. Top with whipped cream, then carefully add remaining brownie mixture to form another layer. Top with custard. Cover and chill for at least 2 hours.
