Beat the caster sugar and egg yolks together in a mixing bowl until a thick yellow paste forms.
Simmer both types of milk in a saucepan and slowly beat into the egg mixture.
Stir the mixture over gentle heat until it reaches a custard consistency, then strain and chill overnight.
Stir in double cream, vanilla, ginger, and cardamom before churning in an ice cream maker.
Preheat your oven to 170°C.
Melt muscovado sugar and butter together, then stir in honey, chopped pecans, egg, and cinnamon.
Transfer the mixture into the tartlet cases and top with whole pecans.
Bake the tarts for 20 minutes.
Serve warm tarts with a scoop of ice cream and a drizzle of maple syrup.