Beat the sugar with the eggs until creamy and incorporated.
Heat the milk in a large saucepan until it just begins to steam.
Pour the milk into the egg mixture, a little at a time, while stirring continuously, to ensure that the eggs do not scramble.
Return the mixture to the stove and add the vanilla extract, seeds and walnut oil. Keep stirring the mixture until it thickens slightly. The custard is done when it is thick enough to coat the back of a spoon and when a finger drawn across the film leaves a clean path.
Stir in the walnuts at this stage. Remove from the heat and cool to room temperature.
Stir in the cream once cooled and leave to chill in the fridge for about 12 hours or overnight. This waiting time will ensure that the flavours ripen and that the mixture is at an optimal temperature for churning. Churn the mixture while preparing the cake base.
Preheat oven to 180 degrees Celsius. Line and grease a 23 centimetre spring-form pan.
Beat Stork Bake and sugar until light and creamy. Beat in eggs with the lemon essence, one at a time. Fold in flour and baking powder until well combined.
Spoon mixture into prepared pan and bake for 20 minutes or until firm (must still be a bit springy to touch). Leave to cool and turn out onto a wire rack. Wash and dry the springform pan. Line the sides with a strip of wax wrap or parchment paper.
Slice off the top of the cake and set aside for another use. Place the trimmed cake, cut side down into the pan.
Freeze for ten minutes. Remove from freezer. Spread the just-churned walnut ice cream over this. Keep in freezer until topping is ready.
Whip the cream until it forms soft peaks. Fold in lemon curd, lemon juice and the walnuts.
Spoon mixture over the walnut ice cream, cling-wrap and freeze overnight.
Serve with a light chocolate sauce.
Tip: Remove from freezer to soften slightly before serving.