For the Barbados caramel, place all the ingredients in a small saucepan over medium-high heat. Cook, stirring for 2-3 minutes until the sugar has dissolved. Bring to the boil, without stirring, boil for 1 minute then remove from the heat. Pour the caramel into a heatproof jug and refrigerate until cooled to room temperature.
Cut the cheeks from the mangos. Use a large spoon to scoop out the fruit. Cut each mango cheek in half.
Place the mascarpone, yoghurt and vanilla in a bowl, stir gently until just combined. Spoon a little over the base of four serving glasses or bowls. Top with the mango and more mascarpone mixture. Pour over the caramel and sprinkle with biscotti.
TipAny leftover Barbados caramel will keep in the fridge in a clean airtight jar for 6 weeks.