Preheat the oven to 180°C (fan oven).

Line an 8x8 inch square baking tin with greaseproof paper and set aside.

Break the dark chocolate into a microwave-safe bowl and add the butter. Melt in the microwave in 30-second blasts, mixing after each until completely smooth.

In a separate bowl, whisk the eggs and sugar for 30 seconds until pale, thick, and foamy.

Pour the melted chocolate mixture and self-raising flour into the whisked eggs. Gently fold everything together until just combined.

Fold in the shortbread chunks, coating them in the brownie mixture.

Spoon into the baking tin and bake for 20 minutes until the top is no longer shiny and cracks appear.

Leave to cool at room temperature for 30 minutes, then refrigerate for 1 hour.

Measure all ingredients into a medium saucepan.

Place the saucepan over low heat and stir occasionally until melted into a smooth mixture.

Turn heat to medium to bubble. Stir continuously for 5 minutes until thickened and golden.

Remove from heat and stir for 30 seconds to knock out air pockets.

Pour caramel over brownie base and spread evenly.

Cool at room temperature for 30 minutes, then refrigerate for 1 hour.

Break chocolates into separate bowls and microwave until smooth.

Pour melted milk chocolate on top of the caramel and spread to edges.

Drizzle melted white chocolate on top and swirl together.

Refrigerate to set for 1-2 hours.

Remove the tin from the fridge and let brownies soften at room temperature for 20-30 minutes.

Run a sharp knife under hot water, dry, and slice into 16 squares.