Grease a pie tin and sprinkle raw sugar on bottom of tin and shake to coat. Tear the panettone into strips. Use edges of panettone to line the bottom of the pie tin, pressing them in to form a crust.
Put skillet on medium heat and bring double cream, butter, vanilla and milk to a simmer and remove from heat when butter is melted.
While this is heating up, whisk the eggs and caster sugar in a large bowl. Add cream mixture to eggs while whisking continuously.
Pour 1/3 of mixture onto tart base already in tin. Add the rest of the torn panettone into the bowl of cream mixture for a few minutes to soak up the liquid. Then layer in the tin, dropping in chocolates and jam.
Bake for 25 minutes or until set. Enjoy warm or cold!