Pour the milk into a saucepan and bring it to a boil with the orange zest.

Whisk the sugar with the starch, then add the egg yolks.

Pour the boiling milk over the mixture and whisk.

Return the whole preparation to the saucepan and bring it to a boil.

Add the alcohol and transfer the mixture to the fridge to cool for about 3 hours.

Smooth the cream with an electric whisk.

Beat the egg whites until stiff, adding the sugar in two stages.

Gradually fold the meringue into the pastry cream, gently mix with a silicone spatula.

Preheat the oven to 200°C.

Brush the insides of the ramekins with softened butter, making sure to coat them vertically, and sprinkle the ramekins with brown sugar.

Fill the ramekins to the top, tap them to remove air bubbles, and smooth the surface.

Clean the edges of the ramekins and bake on a hot baking sheet for about 16 minutes at 200°C.