Divide all the cake ingredients in half to make the batter lighter and fluffier. Separate 5 eggs into whites and yolks. Add half the lemon juice and half the salt to the 5 egg whites and beat until stiff peaks form.

Warm 1/2 cup milk and add it to the 5 egg yolks along with 1/2 cup sugar, 1.5 tablespoons butter, and 1 cup flour. Whisk until smooth. Gently fold the beaten egg whites into the yolk mixture a little at a time to form a smooth batter. Let the batter rest. Repeat with the remaining eggs and ingredients, then combine both batters together.

Pour all the batter into a 12-inch (30 cm) baking pan, spreading it evenly. Preheat the oven to 375°F (190°C) for 10 minutes. Bake for 10 minutes. When done, turn the cake out onto a damp towel, flip it over, and quickly roll it up in the towel to help it hold its shape.

Let the cake cool while you prepare the cream and decorations. Chill the whipping cream, then beat it with 1/2 cup powdered sugar until stiff peaks form. Melt 1 tablespoon butter with the chocolate and let cool. When the cream is whipped, divide it in half and mix one half with the melted chocolate. Once the cake is cool, mix some grape jam with a little cream and spread it in the center as filling. Roll the cake back up and drizzle with rum to keep it moist and fragrant.

Cut off the ends of the cake to make branch stumps. Spread a layer of plain whipped cream to cover and attach the branches, then cover the log with the chocolate cream.

Use a fork to create bark patterns on the log. Use a small round piping tip and a shell tip to pipe decorations around the cake. Sprinkle dried coconut to look like snow and add colorful candy balls to resemble berries on the log.

Add more decorations as you like, such as small pine trees or flowers. Good luck making your Bûche de Noël and enjoy a festive Christmas Eve with your family!