To make ice-cream, place milk and basil in a heavy-based saucepan over medium heat and bring to a simmer without boiling. Remove from heat and cool slightly.
Using electric beaters, beat egg yolks, sugar and honey in a large heatproof bowl for 3 minutes or until thick and pale. Gradually beat into the milk mixture in a thin stream, and then return mixture to a clean saucepan.
Place saucepan over low heat and cook, stirring constantly with a wooden spoon, for 8 minutes or until mixture coats the back of a spoon. Remove from heat and set aside to cool. Cover pan with plastic wrap and refrigerate until cold.
Strain mixture into an ice-cream maker and churn for 1 hour according to manufacturers instructions. Transfer to a shallow container and freeze.
To make candied orange, using a vegetable peeler, peel skin from orange and cut skin into think strips.
Place peel strips in a small saucepan of cold water and bring to the boil. Drain. Repeat process two more times.
Place sugar and water in a small saucepan over low heat and stir, without boiling, for 8-10 minutes or until sugar dissolves. Add peel strips and simmer for 45 minutes or until peel is translucent. Drain, then place peels on a rack to dry for 3-4 hours.
To make cake, preheat oven to 190C and grease and line a 20cm round cake pan.
Using an electric mixer, beat butter and sugar until pale and creamy. Add eggs, one at a time and beating well after each addition, then fold in remaining ingredients.
Pour mixture into prepared pan and bake for 50-55 minutes or until a skewer comes out clean when inserted into the centre.
Meanwhile, to make orange syrup, place all ingredients in a medium saucepan over low heat and stir, without boiling, until sugar dissolves. Increase heat and boil for 8 minutes or until syrupy. Drizzle half the syrup over hot cake in pan. Reserve remaining syrup.
To make candied orange and toffee shard, line a baking tray with baking paper. Place sugar and water in a small heavy-based saucepan over medium heat and stir, without boiling and using a wet pastry brush to brush any stray grains on side of pan back down into mixture, until sugar dissolves. Bring to the boil and boil, uncovered and without stirring, until mixture turns golden brown.
Pour caramel in a thin layer onto prepared tray. Sprinkle with candied orange, and then allow to set. Break into shards.
Drizzle cake with reserved syrup and serve with ice-cream, caramel and candied orange.