Line a baking tray with foil. Place the sugar and 80ml (1/3 cup) water in a small saucepan over low heat and stir until sugar dissolves. Increase heat to medium and cook, without stirring, for 3-4 minutes or until dark golden. Carefully pour over the mixture to prepared tray and set aside to cool completely. Break toffee into shards.
Pour the custard, vodka, cream and schnapps into a large jug. Stir to combine.
Pour a caramel sauce onto a small plate. Dim the rims of serving glasses into the sauce to coat. Fill glasses with ice cubes then pour in the custard mixture. Serve topped with toffee shards.
