Cream the butter and sugar together until light and fluffy.
Add the self-raising flour and a pinch of salt, and mix until just incorporated.
Spread the dough evenly into a pre-buttered and foiled tray.
Bake at 180 degrees Celsius for 18-20 minutes, or until light golden brown.
While the shortbread bakes, make the caramel: heat caster sugar in a pan over medium heat until melted and caramelized to a deep color.
Gradually add warm cream to the caramelized sugar, stirring constantly until combined and smooth.
Pour the caramel over the cooled shortbread base.
Optionally, sprinkle salt over the caramel.
Chill the caramel and shortbread in the fridge for about two hours until set.
Trim the edges of the set shortbread and caramel slab.
Cut the slab into Twix-sized pieces.
Temper the milk chocolate using the seeding method: melt 800g milk chocolate, add ¼ of tempered chocolate seed, and stir until melted and below 34 degrees Celsius.
Coat the Twix pieces in the tempered chocolate.
Decorate the chocolate-coated Twix bars: spray with silver luster dust, paint a stripe of white colored cocoa butter, then a stripe of red colored cocoa butter over the white stripe.
Use a toothbrush to flick white colored cocoa butter over the bars for a freckled effect.
