Start off by lining the bases of three to four 4.5 inch (12cm) round cake tins with non-stick (baking) paper. Pre-heat the oven to 170 degrees Celsius (or 150ºC fan-forced).
Melt the butter and dark chocolate in a small saucepan (taking care not to overheat the mixture). Once the butter and chocolate mixture has melted, quickly remove from heat.
Place the caster sugar and cocoa powder in a stand mixer and beat in the milk.
Add the chocolate and butter mixture into the sugar and cocoa mixture along with the vegetable oil until well incorporated.
Beat in the eggs until smooth, stir in the yoghurt and mix in the flour and baking powder.
Pour the mixture into the prepared tins, cover with a slightly domed sheet of aluminium foil and bake for around 40 minutes.
Remove the foil in the last 15 minutes of baking. Once done, skewer the cakes to check if it's cooked.
Remove the cakes from the oven and set aside to cool in the tins. Cover with cling-film (while still warm) to keep it moist.
Whilst waiting for the cake to cool, you can start preparing the salted caramel cream cheese frosting.
In a stand mixer, beat the cream cheese and butter until smooth.
Add in the icing sugar until well incorporated.
Add in the salted caramel and keep churning until you get a smooth consistency. Transfer into piping bag.
When you are ready to start layering the cake, place the first layer of cake on a cake base (or plate).
Start piping the cream cheese in a circular pattern, outside in. Once done, start with the next layer and keep bobbling until you complete all layers.
To stabilise your cake, you can stick in 4 wooden skewers to hold it up. This will also prevent it from sliding around if you are transporting the cake. Do this before you finish garnishing the cake.
Once the top layer of your cake has been sufficiently bobbled, you can then add on some smashed salted caramel popcorn, chocolate chips and more lashings of salted caramel.