Preheat the Oven: Start by preheating your oven to 180 degrees Celsius (or 160 degrees for fan ovens). Grease a baking tray (39 x 26 x 4 cm) to prepare for the cake.

Making the Dough: In a mixing bowl, whisk together the sunflower oil, eggs, sugar, and vanilla sugar until well combined. In another bowl, mix the flour, salt, baking powder, and cocoa. Gradually stir this into the egg mixture, alternating with the milk until you achieve a smooth batter.

Bake the Cake: Pour the prepared dough into the greased baking sheet, smoothing the top with a spatula. Bake in the preheated oven for 20-25 minutes, or until a skewer inserted into the center comes out clean. Once baked, allow the cake to cool completely.

Hollow Out the Cake: Once cooled, use a spoon to hollow out the cake to a depth of about 1 cm. Set aside the scooped-out pieces to use as crumbs later.

Prepare the Filling: In a separate bowl, whip the cream until stiff peaks form. Gradually add the cream stiffener and the packets of vanilla sugar. Gently fold in the dark chocolate shavings to incorporate.

Assemble the Cake: Peel the bananas and cut them in half lengthwise. Place them closely together on the hollowed-out cake base. Spread the whipped cream filling over the banana layer, smoothing it out evenly.

Top It Off: Finally, cover the cream with the reserved cake crumbs. Chill the mole cake in the refrigerator until you’re ready to serve.