Blitz the Digestives in a food processor and add the melted Unsalted Butter, pulse together until combined.
Spread onto the bottom and sides of an 23cm Tart Tin. I usually start on the sides, and then cover the bottom last!
Pour the Double cream and Caster Sugar into a large pan and heat on the hob gently, stir till the sugar has dissolved.
Turn the heat up (medium heat max!) and heat the mixture till it starts to boil gently, stir frequently to stop the mixture from catching on the bottom – let it boil for 1 minute and then turn off the heat.
Stir in the Lemon Zest and Fuice and pour onto the biscuit base – refrigerate for 4+ hours, or preferably overnight so it has time to set properly!
Once set, decorate how you please – I mix 150ml Double Cream with 2 tbsps Icing Sugar and pipe on, and then use some Freeze Dried Raspberries, and some Biscuit Crumbs!
Notes
This is obviously a giant Posset so it takes longer to set then Posset’s in individual glasses so be patient with the setting!
If you want to try a different Citrus flavour then go ahead! Just make sure you stick to the same amount of Zest and Juice so that it will still set!
This will last in the fridge, covered, for 3 days!
You can buy freeze dried raspberries from places such as Waitrose, Lakeland, Sainsburys, or a much bigger amount online!
Also... TOP TIP - I find it's MUCH easier to pour the lemon mixture into the tin whilst in the fridge, so I don't have to move the tin after it's full. But I get this isn't possible for everyone!