Hungarian chocolate cream sponge cake a.k.a Lúdláb

For my husband's name day I made him this classic Hungarian chocolate sponge with chocolate cream and sour cherry filling a.k.a Lúdláb ; which translates to "Goose foot". Not sure how the name came about , perhaps the shape?

Thank you Elfrieda for posting an English version of the recipe. I found your version only after translating a Hungarian version...

I'm re-posting her recipe below with my own notes and alteration in brackets { } for my future reference.

Lúdláb

Sponge cake batter:
3 eggs,
3 tbsp caster or superfine sugar
1 tbsp cocoa
3 tbsp cake flour {substitute with 3 tbsp plain flour + 1 tsp baking powder}

Filling:
400 g sour cherry preserves or compote {with some drops of essence of rum}

Chocolate buttercream:
300 ml cream {used only 200ml}
4 tbsp icing sugar
150 g bittersweet chocolate {used about 80g bittersweet (70°%) + cooking choco}
1 tbsp cocoa powder
200 g butter

Fondant:
200 g bittersweet chocolate {omitted - as I decided leaving it out should be fine}

Prepare sponge cake:
Grease 9" cake pan with a small amount of butter and sprinkle a bit of cocoa in the pan to prevent sticking.
Separate eggs, cream yolks with sugar until pale.
Mix flour and cocoa in a separate bowl.
Beat egg whites separately until stiff.
Gently combine wet and dry ingredients.
Bake in 180 C/350 F oven in round cakeform for 25 minutes or until cooked.

For the chocolate buttercream:
Heat cream with sugar, add chopped chocolate and mix until chocolate is melted. Add cocoa. {Beat butter until light and fluffy}
When completely cool, mix with butter(room temperature).

Preparing the Ludlab:
{With cake} still in the cake pan, {spread half the choco. butter cream on sponge}, pour the sour cherry preserves onto the sponge cake, then spread the {remaining} chocolate buttercream on top. Cover with chocolate fondant (simply melted chocolate).

While in the pliable stage, cut the cake into pieces with a heated knife. I waited until the chocolate fondant had hardened and I had a heck of a time slicing the cake.

Allow cake to cool to room temperature or refrigerate for cold Ludlab. It is an extremely rich cake so a small piece for each person is all that you will need. In a regular sized cake pan, count on 14-16 slim slices.

Variation:
Heat sour cherry preserves in small pan and add a tablespoon of brandy or kirsch. Cook for a few minutes to allow alcohol to evaporate, remove from heat and let cool. Smooth over sponge cake as directed above.

Notes
1) With increase sugar by a little
2) will add vanilla extract to buttercream instead of rum.