Step 1
Place half the raspberries in a saucepan over low heat. Cook for 5 mins or until the raspberries collapse. Press through a fine sieve into a heatproof bowl. Discard seeds. Set aside to cool.
Step 2
Grease a 24cm (base measurement) springform pan and line the base and side with baking paper. Arrange the bun bases, cut-side up, over the base of the prepared pan, trimming to fit.
Step 3
Place the milk in a saucepan over medium-high heat. Bring to a simmer. Use an electric mixer to beat the egg yolks and remaining sugar in a bowl until pale and creamy. With the motor on low, gradually add the milk in a thin, steady stream until well combined. Return to the saucepan and cook, stirring, over low heat for 5 mins or until the custard thickens and coats the back of a spoon.
Step 4
Place the chocolate in a large heatproof bowl. Pour the custard over the chocolate and stir until smooth and combined. Stir in the raspberry puree with a few drops of red food colouring to tint the custard light pink.
Step 5
Place the boiling water in a small heatproof bowl. Sprinkle over the gelatine. Stir until the gelatine completely dissolves. Add to the custard mixture and stir to combine.
Step 6
Use a clean electric mixer to beat the cream in a large bowl until firm peaks form. Gently fold into the custard mixture with the remaining raspberries until combined. Pour over the hot cross bun base and cover with plastic wrap. Place in the fridge for 30 mins or until just set.
Step 7
Top the cake with the bun tops (reserve any excess bun tops for another use). Cover cake with plastic wrap and return to the fridge for 3 hours or until completely set. Transfer cake to a serving plate and decorate with white chocolate curls and extra raspberries.