Add the sugar and custard powder to a medium sized bowl. Whisk to combine.
Add the milk and whisk until it’s combined. Microwave for 30 seconds at a time, whisking each time until thickened. Add the vanilla extract and butter in three goes (see notes) and whisk until well combined.
Add the chocolate and mix until well combined.
Run the custard through a sieve to remove lumps. Cover with plastic wrap and chill for 2 hours. Once chilled uncover and whisk to freshen up until smooth.
Raspberry Sauce
Add the raspberries, sugar and lemon juice to a heatproof bowl and microwave for 4 minutes. Run through a metal sieve and discard the seeds. Allow to cool completely.
Whipped Cream
Add the heavy cream, mascarpone and vanilla extract and use an electric hand mixer to whip to stiff peaks. Add the chopped Oreos and fold through. Add to a piping bag.
Chocolate Sauce
Add the baileys to the chocolate sauce and mix to combine.
Assemble
Layer the dessert how’ve you like. I added the chocolate custard and whipped cream to piping bags and the raspberry and chocolate sauce to squeeze bottles. Finish with whipped cream, fresh raspberries and chopped Oreos.
Video
Notes
StorageParfaits can be stored in an airtight container for up to three days and are even better the day after they’re made.ButterI know I added the butter all at once in the video, but I would recommend adding it in 3 lots and whisking each time until it’s well combined to prevent it from splitting the custard.ChocolateI would recommend adding the chocolate while the custard is still warm to ensure it melts. If the mixture cools down too much, and the chocolate won’t melt into the mixture, simply microwave for 20 seconds and mix until melted.