Fluffy Japanese Soufflé Pancakes

Chill the egg whites: Place the two egg whites into a small bowl and put them in the freezer for about 10 minutes. You want them to just start freezing at the edges, which helps create a more stable and voluminous meringue.

Prepare the yolk base: In a medium bowl, whisk one of the egg yolks with the yogurt and milk until well combined. Sift in the plain flour and whisk until smooth, then stir in the vanilla extract. The consistency should be similar to a runny custard. Place this bowl inside a larger bowl filled with ice to keep the batter chilled.

Make the meringue: Melt the butter over low heat and whisk it into the flour mixture. Take the egg whites out of the freezer and whisk them in a stand mixer or with a hand mixer. Gradually add the caster sugar and continue whisking for about 3 minutes until you achieve a thick, fluffy meringue with stiff peaks.

Fold and pipe: Gently spoon the meringue into the flour mixture. Using a large metal spoon or spatula, fold it in very carefully until fully incorporated, taking care not to over-mix and deflate the air. Transfer the batter into a piping bag with a 1.5cm opening.