Preheat the oven to 160°C fan (320°F) and line a large baking tray with parchment paper. Draw a 22cm diameter circle onto the paper and invert it.
Add the egg whites and sugar to a heatproof bowl set over a saucepan of simmering water.
With the egg white mixture set over a double boiler, whisk continuously until the mixture is warm to the touch and the sugar has melted. Check this by rubbing a bit of the meringue mixture between your fingertips to ensure no sugar granules.
Once melted transfer the meringue mixture to a bowl of an electric mixer fitted with a whisk attachment. Beat at medium-high speed for 10 minutes until stiff peaks, the meringue must be thick and glossy.
While the meringue is beating, add the chopped chocolate to a microwave-safe bowl and melt it in the microwave at increments of 20 seconds, be sure to stir often and do not overheat.
Add the melted chocolate to the meringue mixture and swirl the chocolate through using a rubber spatula.
Spoon the meringue mixture onto the prepared oven tray and use the back of a spoon or spatula to push the mixture to the edges of the circle. Create a recess in the middle of the pavlova for the filling.
Bake in the middle of the oven for 1 hour, the pavlova is ready when the edges are crisp and it lifts easily off the baking paper. Turn the oven off and allow the pavlova to cool in the oven for about 3 hours, or overnight.
Assembly
Remove the cooled pavlova from the oven and carefully remove the baking paper from the bottom of the meringue. Place the pavlova onto a serving plate.
Add the chopped chocolate to a microwave-safe bowl and melt it in the microwave at increments of 20 seconds, be sure to stir often and do not overheat. Add the custard and melted chocolate to a mixing bowl and stir to combine. Pour the chocolate custard into the center of the pavlova.
Add the cold whipping cream and icing sugar to a bowl of a stand mixer fitted with a whisk attachment. Beat at medium-high speed until the soft peaks. Spoon the cream over the top of the chocolate custard.
Decorate the pavlova with raspberries and Easter eggs, serve, and enjoy!