Read the recipe and weigh the ingredients
Make room in the refrigerator for the serving plate. Weigh each group of ingredients separately: keep the decoration chocolate separate from the chocolate for the ganache. Cut a sheet of baking paper to the dimensions of the baking tray, with a small edge. Prepare a second sheet of baking paper for turning out the sponge. Cooling stages can overlap; never fill a warm sponge with cream.
Prepare the ganache first
Chop the 300 g of dark chocolate and put them in a dry bowl. Pour the 300 g of cream into a saucepan and heat until the first small bubbles around the edge. Remove from the heat. Pour a third of the cream over the chocolate, wait 30 seconds and then stir with a spatula in small circles in the center. Add the second third and then the last in the same way. The mixture should become smooth and glossy, with no lumps. Do not whisk it.
Let the ganache become spreadable
Pour the ganache into a large container, press cling film directly onto the surface and let cool for about 20 minutes. Then place it in the refrigerator for 30 to 60 minutes, stirring every 10 to 15 minutes. It should hold on the spatula but spread easily without tearing the sponge. If it is runny, chill it longer; if it becomes too firm, leave it at room temperature for a few minutes. Times vary depending on the chocolate.
Preheat the oven and crack the four eggs
Preheat the oven to 180 °C, conventional setting (no fan). Position the oven rack in the middle. Break the 4 eggs one by one in a small bowl to easily remove any shell, then pour them into the large bowl. Add 100 g of sugar and a pinch of salt. It is not necessary to separate the whites from the yolks.
Whisk to the ribbon stage
Beat the eggs and sugar with an electric mixer for 7 to 10 minutes. The mixture should become pale and increase significantly in volume. When you lift the beaters, the falling batter should leave a visible trail on the surface for a few seconds: this is the ribbon stage. If it disappears immediately, whisk for another minute before checking again.
Fold in the dry ingredients without deflating the mixture
Sift the 80 g of flour and the 20 g of cocoa over the bowl in three additions. After each addition, slide the spatula down to the bottom, lift the batter over the top and turn the bowl slightly. Do not use the whisk again. Stop as soon as no pockets of flour remain, checking the bottom of the bowl too. Immediately spread the batter evenly over the entire 30 x 40 cm tray, including the corners.
Bake until set but still flexible
Bake for 10 to 12 minutes. Check after 10 minutes: the surface should be set and spring back slightly when touched, with no wet batter. An overbaked sponge will crack when rolled. Use oven gloves to remove the tray. Rest for a minute, then turn the sponge out onto the second sheet of baking paper. Gently peel off the original baking paper, pulling it back almost flat.
Roll up the warm sponge
With the 30 cm side facing you, make a small initial fold, then roll the warm sponge along its 40 cm length. For this initial roll only, keep clean baking paper between the layers to prevent sticking. Place the roll seam-side down and cool for 25 to 30 minutes. It should be at room temperature before adding the ganache.
Fill and roll without paper inside
Take 220 g of ganache for filling, 280 g for coating and 100 g for fittings and decorations. Gently unroll the cooled sponge, peeling away the paper as you go. Spread the filling, leaving 1 cm clear at the edges and 2 cm at the closing edge. Roll up again using the paper underneath to guide it, keeping the paper outside the cake this time. Place seam-side down, wrap and refrigerate for 45 to 60 minutes.
Cut the stern and stabilize the hull
Cut a 2 cm washer at each end of the cold log. Lay the long seam part underneath on the plate. Glue the two washers to the back, one against the other and supported by the dish, with a part of the reserved 100 g of ganache. Very slightly equalizes the top of the knife roller to create a bridge surface 5 to 6 cm wide. Don't dig the spiral.
Wrap the hull and lay the bridge
Spread 280 g of ganache on the hull and stern. Trace the slats lengthwise with a fork. Melt the 80 g of dark chocolate in a bain-marie and reserve about 20 g for collages. On baking paper, spread the remaining 60 g in a rectangle of about 18 x 6 cm and 2 to 3 mm thick. Mark the slats before taking them completely. Let it harden flat and then lay the bridge on the equalized top with a few ganache points.
Train the cat without keeping it in balance
Take 80 g of white paste for a flat oval disc 6 to 7 cm thick about 8 mm. Add two small triangular ears taken in 15 g of white. With the pink paste, place two triangles in the ears and a small nose. Uses about 5 g of black for two eyes and a simple smile. The disc rests on the flat against the bow; sticks its back with a little ganache, without hidden toothpick.
Add borders and small accessories
Spread about 35 g of red paste into two thin strips of the length of the boat and glue them along the flanks. The rest can form the cat’s scarf. Make a small low buoy with the 20 g of orange and four thin strips taken in 10 g of white. Put it on the deck. With the remaining black, model a chest of 2 to 3 cm maximum and adds a yellow closure; a few small yellow balls evoke the treasure.
Preparing the waves around the hull
Mix only a few turns the 100 g of blue with 40 g of white to keep marbling. Shape two thick ribbons, place them on the flat on either side of the boat and raise small waves with your fingers. Use the remaining 35 g of white for a few rounded ridges. Keep these forms low, supported by the flat, rather than large upright waves.
Making two small sails
Cut two rectangles of 7 x 5 cm edible wafer paper with clean and dry scissors. Paint a red stripe in the center with the minimum dye suitable for the azyme; too much moisture softens it. Let it dry flat. Glue the top of each sail to a 7 cm sponge crossbeam with small dots of reserved chocolate, then glue the crossbeam to its mast. Let it sit flat for 15 to 20 minutes.
Plant the masts at the last moment
With the tip of a small knife, open two small passages in the bridge plate, without pressing the entire plate. Inserts the two masts into the sponge for about 3 cm, one at the front and one at the back. The sails remain small to limit their weight. If a mast moves, use the sails placed on the flat rather than adding a hidden support. Add them just before serving: the azyme and biscuits absorb moisture in the refrigerator.
Present and share
Keep the decorated hull cool, without the masts, until service. Lay the sails, present the boat and then remove the masts and the cat to share them separately. Cut the log into slices with a long knife. All the elements described are food; no wooden sticks or table decor are hidden in the cake.
Storage and serving
Keep the log in a box in the refrigerator and consume it within 48 hours. Take it out for about 15 minutes before serving. Lay fragile decorations at the last moment; do not leave the cream for several hours at room temperature.
Recipe proposal with quantities and step by step. The times are indicative. The video and images illustrate a creation; hand-crafted sets can be simpler.