1. Preheat the oven to 350°F (175°C). Line a 10×15-inch jelly roll pan with parchment paper, leaving a little overhang on the long sides, and lightly grease the parchment.

2. In a large mixing bowl, whip the eggs and granulated sugar together with an electric mixer on high speed for 5–7 minutes, until the mixture is very pale, thick, and has at least doubled in volume.

3. With the mixer on low speed, gently mix in the vegetable oil, vanilla extract, and whole milk just until combined, being careful not to deflate the eggs.

4. In a separate bowl, sift together the unsweetened cocoa powder, all-purpose flour, baking powder, and fine sea salt.

5. Sprinkle the dry ingredients over the egg mixture in two additions, folding gently with a spatula after each addition until no dry streaks remain. Do not overmix.

6. Pour the batter into the prepared pan and spread it into an even layer, smoothing it into the corners with an offset spatula.

7. Bake for 10–12 minutes, or until the top springs back lightly when touched and the edges begin to pull away from the sides of the pan.

8. While the cake bakes, lay a clean kitchen towel on the counter and dust it generously with cocoa powder.

9. As soon as the cake comes out of the oven, run a knife around the edges, then carefully invert the cake onto the cocoa-dusted towel and peel off the parchment paper.

10. Starting from a short side, roll the warm cake up with the towel inside, forming a tight spiral. Place the rolled cake seam-side down on a wire rack and let it cool completely.

11. For the cherry cream filling, add the cold heavy whipping cream, powdered sugar, and vanilla extract to a chilled mixing bowl.

12. Whip the cream on medium-high speed until medium-stiff peaks form. If using kirsch, drizzle it in near the end of whipping and beat just to combine.

13. Once the sponge is completely cool, gently unroll it, leaving it on the towel. If desired, lightly brush the surface with some of the reserved cherry syrup to add moisture and flavor.

14. Spread the whipped cream evenly over the cake, leaving a 1-inch border at one short end so the filling doesn’t squeeze out.

15. Scatter the cherry pie filling or chopped jarred cherries evenly over the whipped cream.

16. Using the towel to help you lift and guide, roll the cake back up from the filled short end into a tight spiral, this time without the towel inside.

17. Wrap the cake roll tightly in plastic wrap and refrigerate for at least 1 hour, or until the filling has set and the cake is well chilled.

18. When ready to serve, unwrap the cake roll and place it seam-side down on a serving platter.

19. Dust the top with cocoa powder and powdered sugar. Spoon the remaining cherries along the top of the roll.

20. Finish with a generous shower of finely shaved or grated dark chocolate.

21. Slice with a long, sharp serrated knife, wiping the blade clean between cuts for neat spirals.