• Note : I recommend checking the steps with images and/or watching the video.

  The recipe might seem long, but that's simply because I’m explaining the steps for two different types of loaf pans.

  You can use a food processor or a stand mixer with a paddle attachment, like a KitchenAid, to prepare the batter.
• Cream the butter, sugar, and salt.
• Incorporate the sifted flour (300 g / 10.6 oz) with the baking powder and mix well.
• Add the eggs one at a time, mixing well after each addition.
• Gradually add the heavy cream once the eggs are fully incorporated into the batter. Mix well to obtain a smooth batter.
• Divide the batter into two equal parts (about 608 g / 21.5 oz each). To do this, weigh the empty bowl you'll use beforehand.
• You should end up with two portions of approximately 608 g (21.5 oz) each.
• Add the cocoa powder (30 g / 1 oz) to one portion and the 15 g (0.5 oz) of flour and vanilla to the other. Mix well.
• Place each batter in a piping bag without a nozzle or a freezer bag.
• Grease and line the bottom and sides of a regular loaf pan, or grease the tube pan along with the tube and inside the lid. Line the bottom with parchment paper.
• Alternate between the vanilla and chocolate batters, starting by piping the vanilla batter in the shape of a W. Then pipe the chocolate batter in the same W shape on top. Watch the video for a clearer explanation.
• Tap the mold gently on the work surface to level the batter.
• Place a small amount of softened butter into a small piping bag or a freezer bag. Pipe a thin line of butter down the center of the batter, along the entire length of the mold.
• Refrigerate the mold overnight, or place it in the freezer for 1 hour if you're short on time.
• After chilling, preheat the oven to 150°C (300°F), preferably with the fan on.
• Bake for 1 hour and 30 minutes, or until a skewer inserted into the center of the cake comes out clean.
• If you choose a tube loaf pan, proceed in the same way.
• Pipe the two batters alternately until you reach the center hole, then insert the tube.
• Continue piping, alternating between the vanilla and chocolate batters.
• Tap the pan gently on the work surface to level the top, and close with the lid.
• Bake immediately for 1 hour and 30 minutes at 150°C (300°F), preferably in a fan-assisted oven.

Soaking syrup:

• Prepare it shortly before the end of the cake's baking time, as it should be lukewarm.
• Combine the water and sugar in a small saucepan and heat over medium heat, stirring until the sugar dissolves.
• Do not let it boil, to avoid evaporating the water.
• Remove from heat and stir in the vanilla extract or rum.

The finishing :

• Unmold the marble cake onto a wire rack.
• For the cake baked in a tube pan, wait about 10 minutes, then gently remove the tube by twisting it first in one direction, then the other.
• Brush the warm cake with the lukewarm syrup on all sides, avoiding the bottom.
• Allow it to release some steam, then wrap it completely in plastic wrap. Let it rest until the next day, or for a minimum of 4 hours at room temperature.

Prepare the ganache

• The next day, prepare the dark chocolate ganache if you baked a marble cake in a tube loaf pan. If not, proceed directly to the chocolate Rocher glaze step.
• Melt the dark chocolate over a double boiler. While the chocolate melts, heat the heavy cream together with the inverted sugar or honey.
• Add the hot cream to the melted chocolate in 3 or 4 stages, stirring in a circular motion with a spatula. The ganache may appear to separate at first, but this is normal. Continue adding the remaining cream until the ganache is smooth and glossy.
• You can use an immersion blender, taking care not to incorporate air bubbles. Transfer the ganache to a piping bag.
• Remove the plastic wrap from the cake, then wrap one side tightly. If needed, double the plastic wrap to seal any gaps and prevent the ganache from spilling.
• Place the cake upright in a container that will hold it steady. Fill the central hole with the ganache, which should be liquid but not too runny, filling it to the top.
• Refrigerate for about 15 minutes, then add more ganache if necessary, as it may settle slightly.
• Freeze the cake with the ganache in this position for 1 to 2 hours to make glazing easier. If you made a cake without ganache, freeze it as well for 1 to 2 hours.
• This thermal shock will help the glaze adhere to the cake, allowing you to pour hot glaze smoothly without forming clumps.

Rocher Glaze

• Roast the finely chopped blanched almonds for about 15 minutes in a preheated oven at 160°C (320°F), then let them cool.
• Melt the chocolate in a double boiler. Once melted, stir in the oil until fully combined. Remove from heat, then fold in the toasted almonds.
• Place a wire rack over a tray lined with two sheets of aluminum foil. The foil will catch any excess glaze, allowing you to pour it back over the cake.
• This step should be done quickly, before the glaze starts to set on the cake. Remove the cake from the freezer and place it on the wire rack. Pour the glaze over the entire cake to cover it completely, and pour any excess from the tray back over the cake. This ensures a generous layer of glaze.
• Gently tap the rack to help the glaze spread evenly. Avoid using a spatula, as it can leave marks.
• Slide two large spatulas under the cake and carefully transfer it to a serving platter once the glaze has stopped flowing.
• Allow the cake to sit at room temperature before serving.