Step 1

Preheat oven to 200°C. Brush four 125ml (1/2-cup) capacity ovenproof ramekins with melted butter to lightly grease. Lightly dust with sugar. Place a baking tray in the oven.

Step 2

Melt the butter in a medium saucepan over medium heat until foaming. Add the flour and cook, stirring, for 1-2 minutes or until mixture bubbles and begins to come away from the side of the pan. Remove from heat. Gradually pour in half the milk, whisking constantly with a balloon whisk until mixture is smooth. Gradually add the remaining milk, whisking until smooth and combined. Place the saucepan over medium heat and bring to the boil, stirring constantly with a wooden spoon, for 2 minutes or until mixture thickens and leaves the side of the pan. Remove from heat. Add the chocolate and stir until smooth and combined. Stir in the liqueur and egg yolks.

Step 3

Use an electric beater to beat the egg whites in a clean, dry bowl until firm peaks form. Add the sugar and beat until sugar dissolves. Add one-quarter of the egg white to the chocolate mixture and use a large metal spoon to fold until just combined. Add the remaining egg white and fold until just combined.

Step 4

Pour the mixture evenly among prepared ramekins. Run your finger around the inside rims of the ramekins in the souffle mixture.

Step 5

Place souffle on preheated baking tray in oven and bake for 10 minutes or until golden brown and puffed. Remove from oven and serve immediately.