Make the jelly according to the instructions on the pack and then pour into an 8inch (3.25 litre) trifle dish.
Cover with cling film and place in the fridge to set completely while you prepare the rest of the layers.
Make the custard by placing the cream and vanilla bean and seeds in a small pot over a medium high heat and bring to a vigorous simmer.
While the cream is heating, whisk together the sugar, egg yolks and corn flour in a large bowl.
When the cream is hot, slowly pour into the egg mix, whisking continuously until combined.
Transfer the mix back into the pot and place over a low heat, stirring every now and then for 6 minutes until the custard is thickened.
Remove from the heat and place a sheet of cling film directly on top of the custard to prevent a skin from forming. Set aside and allow to cool completely.
Line an 8inch cake tin with parchment paper and then press the christmas cake crumbs in so you have a flat surface. Pour over the alcohol and allow to soak through.
Whisk the cream in a large bowl until it just forms peaks, place in the fridge until you are ready to assemble.
Toast the almonds in a frying pan over a medium high heat for about 3 minutes. Make sure not to burn them. Remove to a plate and allow to cool completely.
When the jelly has set, carefully layer the christmas cake base on top of the jelly. You can cut it into quarters for easier assembly if you wish.
Top with the custard and then the whipped cream.
You can place the trifle back in the fridge at this stage or serve straight away with a sprinkle of toasted almonds.