Preheat the oven to 250°F. Line a baking sheet with parchment paper and set aside. Add the egg whites to the bowl of a stand mixer. Whip the egg whites on high speed with a whip attachment. When the egg whites begin to stiffen and create soft peaks, begin to slowly add the sugar. Add the sugar in several small increments.
Once the sugar is fully incorporated, continue beating the egg whites until it has dissolved completely. You can tell if the sugar is dissolved by rubbing a little meringue between two fingers – it should feel completely smooth with no grains of sugar in it. If you still feel the sugar, continue to beat the meringue. This will take 5 to 8 minutes.
Meanwhile, combine the cornstarch, vinegar, and vanilla in a small bowl and stir until the cornstarch is dissolved. When the sugar has been fully dissolved into the egg whites, turn the speed down to low. Add the cornstarch mixture and then turn up the speed. Mix until the cornstarch mixture is fully incorporated.
Spoon the meringue onto the prepared baking sheet and shape into a 7 or 8-inch circle; the meringue will spread as it bakes. Use a teaspoon to create a shallow indent in the middle of the circle for the filling while building up the rim slightly. Drag the teaspoon up the outer edge of the pavlova to create a decorative edge.
Bake the meringue for 1 hour. After 1 hour, turn the oven off and leave the meringue in the oven for another hour, then remove and allow to cool completely.
Poach the pears while the meringue is baking. Peel the pears and cut in half, leaving the stem intact if possible. Use a melon baller or metal spoon to scoop out the inner core. Use a vegetable peeler to peel half the rind off the orange. Use a zester to remove the remaining zest from the orange and reserve for the whipped mascarpone cream. Juice the orange.
In a saucepan, combine the red wine, cranberry juice, orange juice, orange liqueur, and sugar. Add the ginger slices, orange peel strips, cinnamon sticks, star anise, and whole cloves. Place over medium high heat. Add the pears and bring to a simmer. Turn down the heat, cover, and simmer on low for 20 to 30 minutes until the pears are tender when pierced with a paring knife. Use a spoon to flip the pear halves a few times to encourage even poaching.
When the pears are cooked, remove from the poaching liquid with a slotted spoon. Transfer the pears to a plate and let cool. Strain the poaching liquid into a clean saucepan and discard the spices. Bring the poaching liquid up to a boil. Continue to boil, uncovered, until it reduces down to a syrup. This should take 10 to 15 minutes.
Reduce the liquid down to about 1 cup – it should be slightly syrupy in consistency. The syrup will thicken even more once it cools. Chill the pears and reduced syrup before serving.
In the bowl of a stand mixer, combine the heavy cream and icing sugar. Beat with a whip attachment until soft peaks. Add the mascarpone, orange liqueur, and reserved orange zest and beat just until combined and the mixture has stiff peaks.
Carefully transfer the meringue to a serving platter. Pile the whipped mascarpone cream on top of the meringue, spreading to the edges. Arrange the pear halves on top and drizzle with some of the reduced syrup. Cut the pavlova into wedges and serve with the remaining syrup. Enjoy!