Preheat your oven to 350 degrees Fahrenheit. Lightly butter a 10 x 15-inch jelly roll pan and line it with parchment paper, ensuring the paper hangs over the sides for easy removal later. Lightly butter the parchment paper as well.

In a medium bowl, whisk together the flour, baking powder, salt, and cocoa powder, then set it aside.

In a stand mixer, combine the sugar and butter. Mix on medium speed for about 30 seconds, then increase to high speed and mix for another 30 seconds until smooth.

Add the eggs and vanilla, mixing for about 30 seconds until well blended.

Gradually add the dry ingredients, beating on low and then medium speed until thoroughly combined, being careful not to overmix.

Using an offset spatula, spread the batter evenly in the prepared pan, making sure to reach the corners. Shake the pan gently to help level the batter.

Bake for 10 to 12 minutes, or until the cake springs back when touched.

Once baked, allow the cake to cool for about a minute before running a sharp knife around the edges. Using the parchment paper, lift the cake from the pan and place it on a heatproof surface.

With the cake still warm, roll it from one short end to the other, using the parchment to assist. This will help prevent cracks when you unroll it later.

Place the rolled cake seam-side down in the refrigerator to cool completely.

While the cake cools, prepare the filling. In a mixer, whip the heavy cream on low speed until it thickens slightly, then turn to high speed to form stiff peaks. Set the whipped cream aside.

In the same bowl, beat the cream cheese until smooth and lump-free, then add the powdered sugar and vanilla, mixing well.

Carefully fold in the whipped cream until just combined.

Once the cake is cooled, gently unroll it. Spread the filling evenly, leaving about a half-inch border. Roll the cake back up, discarding the parchment and wrapping it tightly in plastic wrap. Chill it for at least 30 minutes.

For the ganache, chop the chocolate and place it in a bowl. Heat the cream and corn syrup in the microwave until just bubbling around the edges.

Pour the hot cream over the chocolate, allowing it to sit for a minute, then whisk until smooth. Chill the ganache until it's cool and pourable.

Remove the plastic wrap from the cake and place it on a wire rack over a lined cookie sheet. Pour the ganache over the cake, making sure it covers evenly.

Refrigerate again for at least 30 minutes to set.

Finally, slice the cake into even pieces with a sharp knife, cleaning the blade after each cut for a beautiful presentation. Enjoy!