Step 1

Preheat oven to 180°C/160°C fan-forced. Lightly grease a 24-hole, 1 1/2 tablespoon-capacity mini muffin pan.

Step 2

Place butter and dark chocolate in a large heatproof microwave-safe bowl. Microwave on MEDIUM (50%) for 2 to 3 minutes, stirring every minute with a metal spoon, or until melted and smooth. Stir in sugar. Stand for 10 minutes to cool slightly. Whisk in eggs and vanilla. Sift over flour and cocoa. Whisk to combine.

Step 3

Divide mixture between prepared holes. Level tops with a small spatula or spoon. Bake for 12 minutes or until tops are firm. Stand in pan for 5 minutes. Turn top-side down onto a wire rack to cool completely.

Step 4

Place white chocolate in a heatproof microwave-safe bowl. Microwave on MEDIUM (50%) for 1 to 2 minutes, stirring every 30 seconds with a metal spoon, or until melted and smooth. Drizzle teaspoons of melted chocolate over each brownie to form 'custard'. Top with 2 pieces green glace cherry to make holly leaves and a few pieces of red glace cherry for berries. Stand for 20 minutes or until chocolate has set. Serve.