Cake: Preheat the oven to 160 degrees C. Grease and line two Swiss roll tins with baking paper.
In a mixing bowl, combine the egg yolks with the caster sugar and vanilla sugar then whisk until pale and creamy.
In a separate bowl mix the flour, semolina, cocoa powder and baking powder.
To the egg yolk mixture add the milk, oil and honey then sift in the flour mixture gradually until smooth.
Beat the egg whites with a pinch of salt until stiff peaks form, then fold in to the cake mixture. Divide the mixture between the two cake tins.
Bake in the preheated oven for 15 minutes or until a skewer inserted into the centre comes out clean and the cake is springy to the touch. Allow to cool completely.
Milk Filling: In a bowl mix the condensed milk with 50ml of the milk.
Put the rest of the milk in a saucepan and add the gelatine powder, stirring to dissolve over a low heat, then add to the condensed milk. Mix in the honey and vanilla extract.
In a bowl, whisk the cream until thick then add to the rest of the ingredients. Put the cream in the fridge for 30 minutes.
To Assemble: Once the cakes are cool, spread the milk filling over one of the cakes then very carefully add the second cake layer, using the baking paper to help you lift it out of the tin and lay it on top.
Put the cake in the fridge for at least 2 to 3 hours. Cut it into rectangles and it's ready to serve.