Creating this Swiss roll involves several steps, but with careful attention to detail, you’ll end up with a dessert that’s sure to impress.

1. Make the Cake:

1. Preheat your oven to 375°F (190°C). Prepare a 10×15-inch baking sheet by lining it with parchment paper and greasing it lightly.
2. In a bowl, combine the flour, cocoa powder, baking powder, and salt.
3. In another large bowl, beat the eggs and granulated sugar until the mixture is fluffy and pale.
4. Gently fold the dry ingredients into the egg mixture, ensuring not to deflate the batter.
5. Stir in the vegetable oil and vanilla extract until well combined.
6. Spread the batter evenly onto the prepared baking sheet.
7. Bake in the preheated oven for 10-12 minutes or until the cake is set and springs back when touched.

2. Roll the Cake:

1. Dust a clean kitchen towel with powdered sugar.
2. Once baked, flip the cake onto the towel and carefully remove the parchment paper.
3. Roll the cake up with the towel while it’s still warm. This prevents cracking and helps the cake maintain its shape.
4. Allow the cake to cool completely while rolled.

3. Make the Filling:

1. Whip the heavy cream with powdered sugar and vanilla extract until soft peaks form.
2. Unroll the cooled cake and spread a layer of chocolate ganache over it, followed by the whipped cream. Leave a small edge free to prevent overflow.
3. Roll the cake back up without the towel, finishing with the seam side down.

4. Prepare Ganache:

1. In a saucepan, heat the heavy cream until it begins to simmer.
2. Remove from heat and add the chopped chocolate, stirring until smooth.
3. Mix in the butter until fully melted and incorporated.

5. Finish:

1. Pour the ganache over the rolled cake, spreading it evenly to cover the surface.
2. Refrigerate the cake for at least 30 minutes to allow the ganache to set.
3. Slice and serve, optionally garnishing with extra whipped cream or chocolate shavings.