Add sugar, water and orange juice to a large and deep frypan and bring to a boil. Thinly slice the oranges using a mandolin or a sharp knife. About 5mm thin. Place the orange slices in the frypan. Allow to simmer away for 30-40 minutes then use tongs to take out of the frypan and place on a cooling rack or baking tray lined with baking paper. Allow to cool.
To coat, simply dip half of each orange slice in melted dark chocolate. Place bag on a baking tray and allow the chocolate to set.
Preheat a fan-forced oven to 140°C / 275° for a conventional oven to 160°C / 320°F. Line two cupcake tins with white cupcake liners.
Add the butter and sugar to a large mixing bowl. Use electric beaters to beat until light and fluffy. About 3 minutes. Scrape down the bowl and add the egg. Beat until well combined.
Add the salt, Greek yogurt and vanilla extract and beat in. Scrape the bowl down and add half the flour, all the baking powder, oil and half the milk. Mix on low speed until well combined. Then add the remaining milk and flour and repeat. Lastly, add the orange zest and orange juice and fold through using a spatula.
Line a cupcake baking tray with cupcake liners. Fill cupcake liners with batter, about 3/4 of the way. Bake for 40 minutes or until a toothpick inserted into the center of the cupcake comes out clean. Allow to cool in the baking tray for 5 minutes before transferring to a cooling rack to cool completely.
Add all the ingredients to a heat proof bowl and microwave for 30 seconds at a time, stirring each time until smooth.Allow to cool to room temperature before using.=
Add the chocolate and heavy cream to a medium sized heatproof bowl and microwave for 30 seconds at a time, until smooth. Set aside to cool at room temperature.
To a separate, large bowl, add the butter and use an electric hand mixer to beat until pale and fluffy. About 3 minutes.Add the sugar and vanilla extract. Begin beating on low speed until sugar is mixed. Turn mixer to high speed and beat for 5 minutes until pale and fluffy. Scrape down the bowl using a spatula and add the cooled chocolate mixture and beat in until well combined.
Add the frosting to a piping bag fitted with an open star tip. Core the center of each cupcake and fill with chocolate sauce. Frost each cupcake with a swirl. Drizzle with more chocolate sauce and finish with a slice of candied orange.
Cupcakes can be stored in an airtight container for up to three days. They’re quite tall, so you can store them in a container, frosted, without the candied oranges and pop the orange slices on before serving.