Boil 1 litre of water with 450g sugar in a pan.
Soak gelatine leaves in cold water until soft.
Measure 1 litre of the hot syrup and stir in the squeezed gelatine to dissolve.
Add raspberry cordial and vodka to the syrup mixture.
Oil two 500g terrine moulds and line with cling film overhanging by 2cm.
Set the moulds on ice and layer jelly and raspberries in stages to set.
Refrigerate the terrines for at least four hours.
Boil milk, cream, and vanilla seeds, then whisk egg yolks and sugar together.
Pour hot cream over eggs while stirring, then cook until thickened.
Sieve the custard into a bowl to cool, then churn in an ice cream maker.
Store the churned ice cream in a sealed container in the freezer.
Simmer 200ml reserved syrup with lime cordial and thicken with arrowroot dissolved in water.
Remove sauce from heat and stir in lime zest to cool.
Slice the jelly and serve with raspberries, ice cream, and lime sauce.