Set saucepan over low heat and add two tablespoons of water to it. Add sugar, raspberries and close the lid of the pan.

Cook for about 5 to 6 minutes. Blend these cooked raspberries to form a smooth puree and pass them through a sieve to get a smooth raspberry juice. Add water and liqueur (if using)to dilute it and transfer it into a jug.

Add two leaves of gelatin to a bowl containing cold water and let it soak for about 4 to 5 minutes. Boil the diluted raspberry juice in a saucepan and remove the excess liquid from the pan after turning off the heat.

Now, add gelatin to this pan and whisk it. When it’s completely dissolved, transfer it to a large trifle bowl or a large glass serving bowl. Keep it in the refrigerator for at least 3 hours until it’s firm.

Again set a saucepan over medium heat. Add cream and vanilla seeds to this pan and bring the cream to boil. Now, lightly whisk the egg yolks in a large bowl and stir in half of the warm cream in it. Pour this egg mixture into the saucepan over low heat. Continue whisking the egg mixture until it’s thick. Transfer this egg custard to a jug or a large bowl. Cover the rim with a cling film and refrigerate it until needed.

Remove the jelly and custard from the refrigerator. Lay the sponge fingers over the jelly. Spread some raspberries over them and pour over the egg custard. Spread the whipped cream all over the custard and refrigerate this trifle for a few hours. Top with raspberries and serve.