Whisk cream, milk, bourbon (optional) and spices together in a medium saucepan over medium-low heat until mixture just comes to the boil, stirring occasionally. Turn off heat. Set aside for 10 minutes to infuse the flavours. Remove and discard cinnamon quill.

Meanwhile, beat egg yolks, sugar and vanilla together in a large bowl with electric beaters until pale in colour and thickened. Mixture should fall in thick ribbons when lifted with the beaters. Slowly whisk in 1 cup of the warmed cream mixture.

Pour egg yolk mixture into the saucepan containing the warmed cream and heat over medium-low heat. Cook, stirring constantly, for 10-12 minutes or until mixture thickens enough to coat the back of a spoon. Ensure that it doesn’t boil.

Remove pan from the heat and strain through a fine mesh sieve into a heatproof bowl. Cover the surface of the custard with plastic wrap. Cool for 1 hour. Refrigerate overnight.

Preheat oven to 160°C fan-forced. Grease and line base and sides of a 13.5cm x 28.5cm x 7cm loaf pan with baking paper.

Sift flours, bi-carb, ground spices and cocoa into a large bowl and whisk in sugar until there are no lumps of sugar.

Whisk warm butter and treacle in a jug or bowl until smooth. Whisk eggs and milk in a separate jug. Pour treacle/butter mixture along with combined egg milk into flour mixture and stir with whisk until smooth.

Pour into loaf pan and bake for 50-55 minutes or until cooked when tested with a skewer. Allow to cool for 30 minutes before inverting onto a wire rack to cool. Cover and set aside until ready to assemble, preferably overnight.

To Assemble: 1. Churn cold eggnog custard in an ice cream machine according to manufacturer’s instructions until soft serve consistency and spreadable but not runny. 2. Meanwhile, cut cake in half horizontally. Grease and line all sides of same loaf pan with baking paper extending sides by 5cm. Place bottom layer of cake in the base of pan, cut side up. 3. Spread ice cream on top. Top with remaining cake half, top facing up and press down onto ice cream. Cover with plastic wrap. Place in the freezer overnight.

Allow reserved egg whites to come to room temperature.

Place sugar and water in a small saucepan over a medium heat and stir until sugar dissolves. Bring to a rapid simmer. Without stirring, brush down sides of saucepan with a wet pastry brush to remove any sugar crystals.

Place a sugar thermometer in pan whilst continuing until it reaches soft ball stage 116°C (240F) on thermometer. Remove from the heat and stand for 5 minutes.

Place egg whites and juice in the bowl of an electric mixer. Beat until egg whites are thick and white. Very slowly, drizzle in hot sugar syrup while mixer is beating and meringue becomes thick and glossy. Continue to beat after syrup has been added until firm peaks form. This should take about 10 minutes.

Lift loaf onto a serving platter or board and remove baking paper. Spread meringue all over, forming peaks and swirls. Use a kitchen blowtorch to lightly scorch the meringue.

Cut into thick slices and serve immediately or keep in the freezer until ready to serve up to 3 days.