Preheat your oven to 300°F (150°C) and line a baking tray with parchment paper.

In a stand mixer bowl, beat the egg whites on high speed until soft peaks form (about 2-3 minutes). Gradually add the caster sugar, beating until thick and glossy (roughly 5-7 minutes).

Gently fold in the cornstarch and white vinegar with a spatula. Be careful not to deflate the meringue.

Spoon or pipe the meringue mixture onto the prepared parchment paper, forming tall domes about 3 inches wide and creating a small well in the center.

Reduce oven temperature to 225°F (110°C) and bake meringues for 1.5 hours until they dry out without browning.

Turn off the oven and leave the Pavlova Bombs inside for 3 hours or overnight to cool gradually.

Once cool, cut a hole into the flat base of each Pavlova Bomb to create a cavity for filling.

Pipe raspberry coulis into the cavity, followed by lemon curd, and seal with whipped cream.

Flip filled Pavlova Bombs onto plates, adding extra whipped cream, fresh berries, pistachios, and powdered sugar to serve.