Whisk eggs, sugar, hot water and vanilla until light and creamy.
Sieve flour and baking powder and fold in egg mixture.
Spread evenly on baking tray with baking paper.
Bake in preheated oven at 180° C for about 16 to 18 minutes.
Leave to cool.
Dissolve vanilla custard powder in some orange juice.
Bring rest of orange juice to boil.
Pour in dissolved custard powder while stirring.
Bring to boil and remove from fire.
Spread warm orange custard on sponge base
Put in a cool place.
Whisk cream, vanilla and cream stiffener until stiff.
Spread on custard layer.
Dip ladyfingers in a orange juice-rum-mix and arrange on whipped cream.
Chop chocolate and put with the coconut oil in a freezer bag.
Hang freezer bag in hot water until it is melted and squeeze a bit to mix. Cut off the tip and pipe stripes on the ladyfingers.
Leave to cool down.
I like to use a baking frame on the baking tray, but this is not really necessary, you can do without.