Preheat the oven to 130°C ( 250°F). Line a large baking sheet with greaseproof paper and draw two 8-inch circles, spaced slightly apart. You might need to use two baking sheets depending on the size of your baking sheets/oven.
Put the Demerara sugar in a food processor or blender and blitz to create a finer grain. You don’t want to turn it into powder, just blitz until the granules are smaller.
Using a stand mixer with the whisk attachment, beat the egg whites on medium-low speed until frothy, then add the cream of tartar.
Increase the mixer speed to medium-high and beat to soft peaks.
Gradually add the Demerara sugar a couple of tablespoons at a time.
Continue beating on medium speed until the meringue is glossy and stiff peaks form. Feel a bit of the meringue between your fingers – it should not feel grainy. If it does, continue to beat for a bit longer.
Add the cornstarch (cornflour), lemon juice and vanilla and whisk for a couple minutes to combine evenly.
Divide the meringue evenly between the two circles, using a spatula to form a circular shape. Any leftover meringue can be piped to form meringue kisses.
Bake the meringue for 10 minutes then reduce the temperature to 90°C (200 °F) and continue to bake for 1 hour and 20 minutes. Leave the meringue in the oven until completely cool.
Store the cooled pavlova layers in an airtight container for up to three days.
Make the caramelised peaches
Heat the butter in a skillet. Add honey and vanilla paste once butter starts to foam.
Add peach slices and simmer until they start caramelising, turning them over gently to coat in the sauce.
Add a generous splash of bourbon before taking off the heat.
Transfer to a plate to cool before assembling the pavlova.
Make the Whipped Cream
Place the cream, icing sugar and vanilla paste in the bowl of your stand mixer fitted with the whisk attachment.
Whisk at medium-high speed until it holds soft peaks, keep an eye on it so that it doesn’t over whip.
Keep in the fridge until ready to use.
Assemble the pavlova
Place the bottom pavlova layer on a serving plate or cake stand.
Add half of the whipped cream and a layer of peaches plus some of their caramel syrup.
Top with the second pavlova layer and add the remaining whipped cream, piling more peaches on top.
Drizzle with any remaining syrup and serve immediately.
Replace Demerara with turbinado sugar or use 1 cup granulated or caster sugar and 1/3 cup dark brown soft sugar.
Replace the peaches with nectarines, plums or apricots. Or use apples or pears cooked for slightly longer until soft.