- all-purpose flour for dusting
 - 2 sheets puff pastry
 - 24 ounces mascarpone cheese, at room temperature
 - 3 large grapefruit, segmented and juice reserved
 - 5 oranges, segmented and juice reserved
 - 1 vanilla bean
 - 4 teaspoons sugar plus
 - 1 1/4 cups sugar for syrup
 
- Preheat oven to 190 degrees C/ 375 degrees F.
 - Lightly dust a work surface with flour.
 - Cut 8 disks of puff pastry approximately 8cm/4 inches in diameter.
 - Place the pastry discs on a silicone mat or parchment paper lined baking sheet. Grease the bottom of a second smaller baking sheet. Place the smaller baking sheet on top of the first weighing down the pastry discs.
 - Bake in the oven for 15-20 minutes or until the pastry is golden.
 - Remove the top baking sheet and sprinkle each pastry disc with 1/2 teaspoon of sugar.
 - Place under the broiler and dissolve sugar, taking care not to burn pastry. Allow pastry discs to cool.
 - Place the mascarpone in a mixing bowl. Add 2 tablespoons of reserved citrus juice and whisk until smooth. Refrigerate until ready to use.
 - Split the vanilla bean lengthways and remove seeds. Reserve empty pods.
 - Place vanilla seeds, reserved vanilla pods, remaining citrus juice and sugar in a saucepan. Bring mixture to a boil over medium heat.
 - Reduce heat to a simmer and cook until liquid is reduced and thick, about 10 minutes. Allow mixture to cool.
 - Remove vanilla pods.
 - Place 4 pastry discs on 4 dessert plates.
 - Spoon 1/4 of the mascarpone mixture onto each disc.
 - Place remaining pastry discs on top of the mascarpone to form 4 sandwiches.
 - Spoon the segments of fruit on top of sandwiches and drizzle with syrup.