Place egg yolks and sugar in a bowl and whisk with electric beaters until thick and pale. Set aside.
Place the pure cream in a saucepan over medium heat and bring to just below boiling point. Pour the hot cream over the yolk mixture, stirring to combine, then return to a clean saucepan and cook over low heat, stirring constantly, for 3-4 minutes until the mixture is thick enough to coat the back of a spoon. Remove from the heat, then strain into a bowl and cover the surface closely with a piece of baking paper. Set custard aside to cool completely.
Lightly whisk the thickened cream to soft peaks, then fold through the custard, with the vanilla, nutmeg, rum and brandy. Transfer to an ice cream machine and churn according to the manufacturer's instructions. (Alternatively, pour mixture into a shallow container and freeze for 2 hours until frozen at the edges. Beat with electric beaters, then return to the freezer. Repeat 2-3 times.)
Line eight 1/2 cup (125ml) dariole moulds or shallow plastic containers with plastic wrap. Transfer the ice cream to the moulds and freeze for at least 4 hours or overnight until firm.
To make walnut crumbs: Preheat the oven to 180°C and line a baking tray with baking paper. Place flour, sugar, cinnamon and nuts in a food processor and whiz to combine. Add butter and pulse until the mixture comes together in large clumps. Spread onto the baking tray and bake for 20 minutes, stirring once, or until golden. Allow to cool, then break into small clumps and serve.
To serve, turn the ice creams out onto a platter, peeling away plastic wrap. Scatter with raspberries and walnut crumbs.
