Preheat oven to 180°C/350°F (160°C fan). Place oven rack in the middle to upper section of the oven. Place cupcake liners in a 12-hole muffin pan. 

To make the cupcakes, in a small jug add golden syrup and cream and stir to combine. Set aside. In a separate bowl add butter and sugar, beat with an electric mixer until pale and fluffy. Add the golden syrup and cream mix, and vanilla extract and mix until combined.  Add eggs, one at a time, beating until combined. Add in the sifted flour, baking powder and salt, beat until combined. Divide the mixture between the liners, until about two thirds full. Bake for approximately 20 mins until a skewer inserted into a cupcake comes out clean, with the exception of a few moist crumbs sticking to the skewer. Transfer immediately to a wire rack to cool. 

Meanwhile, make the ganache. Add chocolate and cream to a microwave safe bowl and heat in short bursts of 10 to 15 seconds at 50% power, stirring each time until smooth. Set aside in the refrigerator to cool. 

Next make the caramel sauce. Place the sugar and water in a medium saucepan and stir over low heat until sugar dissolves. Cook over medium to low heat until sugar changes to a light brown colour. Add butter and stir carefully to melt, the mixture may foam but will settle with stirring. Bring back to a gentle simmer then turn off the heat and add the cream, stirring to combine. The mixture may bubble again at this stage but will settle after cream is combined. Whisk in salt. Allow to cool. 

Next make the frosting. Beat the butter and vanilla extract on high until pale and fluffy. With the mixer on low add the icing sugar gradually, scraping down the bowl from time to time. Add ¼ cup of the cooled caramel sauce. Increase the speed to medium and mix for 2 minutes until smooth.

When cakes are cool, remove centres until about two thirds of the way down, using a corer, melon baller or sharp knife. Fill with ganache using a small spoon. Pipe frosting in a swirl on top. Drizzle with leftover caramel sauce and top with Koko Black salted caramel chocolate eggs.