Begin by dividing 2 eggs into egg yolks and egg whites. Only the egg whites will be used in this recipe.

Whisk the egg whites until they form stiff peaks, creating meringue.

In a separate bowl, combine 70 g of softened butter and 70 g of sugar. Use a rubber spatula to mix them thoroughly.

After the butter and sugar are well combined, sift 70 g of cake flour into the mixture. Stir to fully incorporate the flour.

Carefully fold the meringue into the butter-sugar-flour mixture. This can be done in 3 or 4 portions, ensuring you maintain the airy texture.

Pipe or spoon the mixture into Langue de Chat shapes on an oven sheet lined with parchment paper, leaving space between them.

Preheat your oven to 180 degrees Celsius and bake the cookies for 10 to 15 minutes. Keep a close eye on them and remove when they turn golden.

In a heat-resistant container, combine 80 g of white chocolate, 40 g of heavy cream, and 3-4 drops of vanilla essence. Melt this mixture over a double boiler until smooth.

Fill the Langue de Chat cookies with the white chocolate mixture, then refrigerate until the filling sets.

Now your cookies are ready to be served!