The butter needs to be soft and the eggs at room temperature. Beat the butter with the sugar into fluffy cream. Add the eggs 1 by 1 and beat after each one. Once they're in, add the flavoring - the vanilla, citrus essence, angostura bitters and lemon zest.
Add the marmalade and stir well. Next come the dry ingredients that have been mixed and sifted beforehand - the flour, baking powder, cocoa, cinnamon, spices and pinch of salt. Mix with the melted chocolate, which must not be too hot. Homogenize the mixture, pour it into a suitable tray that has been greased or laid out with baking paper.
Bake the cake in a preheated 356°F (180 °C) oven for an extended amount of time. Check with a toothpick to see if it's ready. The cake has an exceptionally rich flavor and slightly moist inside.
Sprinkle it with sifted cocoa and serve completely cooled.