Step 1: Prepare the Sponge Cake
Preheat your oven to 350°F (175°C). Line a 10×15-inch baking sheet with parchment paper. In a large bowl, whisk together the eggs and sugar until pale and fluffy, about 5 minutes. Add the vanilla extract. Sift together the flour, baking powder, and salt, and gently fold it into the egg mixture until well combined.

Step 2: Bake the Cake
Spread the cake batter evenly onto the prepared baking sheet. Bake in the preheated oven for 10–12 minutes, or until the cake is golden brown and springs back when lightly touched. Once baked, remove from the oven and immediately invert the cake onto a clean kitchen towel sprinkled with powdered sugar. Carefully peel off the parchment paper.

Step 3: Roll the Cake
While the cake is still warm, roll it up gently with the towel inside. Let it cool completely at room temperature.

Step 4: Make the Chocolate Ganache
In a small saucepan, heat the heavy cream over medium heat until it begins to simmer. Pour the hot cream over the chopped chocolate in a bowl. Let it sit for a minute, then stir until smooth and glossy. Add the butter and stir until fully combined.

Step 5: Assemble the Roll Cake
Once the cake has cooled, carefully unroll it. Spread the chocolate ganache evenly over the entire surface. Re-roll the cake tightly, ensuring the ganache stays inside.

Step 6: Serve and Garnish
Place the roll cake on a serving platter. Dust with powdered sugar and garnish with festive toppings such as cranberries, mint leaves, or extra chocolate shavings. Slice and serve!