Preheat oven to 200°C (180°C fan forced).
In a food processor, blitz the biscuits to a fine crumb. Pour in the melted butter and mix to combine. Divide the mixture evenly among jars.
Place the jars onto a lined oven tray and bake for 15 minutes then allow to cool.
In a large bowl, whisk together the egg yolks and condensed milk until thoroughly combined. Whisk in the lime juice and zest, reserving a little zest to decorate. Divide the lime mixture among the 4 jars and return to the oven to bake for a further 10 minutes then allow to cool.
Immediately before serving, in a bowl whisk together the cream, icing sugar and vanilla to stiff peaks. Spoon whipped cream over cooled lime mixture then top with blueberries and the reserved lime zest.