1. Heat your oven to 180C fan-forced (200C conventional). Place the butter in a small saucepan over medium heat and melt. Add the flour and mix with a spatula for about 1 minute until it forms a smooth paste. Add the orange juice and continue to stir over medium heat until the mixture becomes a firm paste and starts to pull away from the pan. Remove from the heat and stir in the orange zest, vanilla and salt. While the mixture is still warm, mix in the egg yolks one at a time, then remove from the pan to a large mixing bowl. 

2. Beat the egg whites to soft peaks, then add half the sugar and beat until combined. Add the remaining sugar and beat until glossy and just holding a ribbon, but not completely firm. 

3. Grease 4 x 1-cup capacity ramekins by brushing with butter at room temperature. Brush the sides vertically from the bottom to the top. Add 2 tbsp of caster sugar to the ramekins and roll around so that the sugar sticks to the butter. Tip any excess from one ramekin to the next and repeat the process to grease all the ramekins. 

4. Fold a third of the egg whites into the egg yolk mixture, then repeat a third at a time, folding more gently for each third. Divide the mixture between the ramekins, filling them right to the top. Run the corner of your thumb around the top of each ramekin to create a channel between the top of the mixture and the edge of the ramekin. 

5. Bake for 12-15 minutes, watching as the soufflés rise and brown on top. Remove from the oven, and dust with icing sugar. Serve immediately. 

Adam's tip When greasing the ramekins, use butter at room temperature, rather than melted. Brushing from bottom to top creates channels of butter which help the souffle to rise. 

Also try Adam Liaw's chicken fricassee