To crush the digestive biscuits, add them to a food bag and and roll over them with a rolling pin. You can also do this in a food processor. Melt the butter in the microwave for around 40 seconds or until fully melted. Pour the melted butter onto the biscuits and add the sugar then mix them all together.
Evenly distribute the biscuit base between the 4 jars and then press the biscuit into the jars using the back of a spoon. Cover the jars with cling film and place the jars in the fridge while you make the filling.
To a stand mixer bowl, add the double cream and whisk to medium to stiff peaks on a medium setting. This could take between 1 minute and 4 minutes but be careful not to over whip the cream.
To another bowl, add the cream cheese, icing sugar, sour cream and vanilla extract then cream them all together. You can do this using an electric hand whisk.
Gently fold the whipped cream into the cream cheese filling and then remove the jars from the fridge. Transfer the cream cheese filling to the jars and spread the filling using a palette knife. Drizzle with salted caramel and sprinkle some crushed digestives on top. Place the jars back in the fridge to set for a minimum of 2 hours then serve.