1. Preheat the oven to 350°F (175°C). Line a 10×15 inch jelly roll pan with parchment paper, lightly grease the paper and sides of the pan, and set aside.

2. In a medium bowl whisk together the flour, cocoa powder, baking powder, and salt until well combined.

3. In a large mixing bowl beat the eggs and granulated sugar with a hand mixer or stand mixer on high speed for 4 to 5 minutes, until thick, pale, and tripled in volume.

4. Gently sift the dry ingredients over the egg mixture in two or three additions, folding carefully with a spatula after each addition so you do not deflate the batter.

5. In a small bowl whisk together the vegetable oil, milk, and vanilla extract, then drizzle this mixture around the edge of the batter and fold in just until smooth.

6. Pour the batter into the prepared pan, spreading it into an even layer all the way to the corners, and tap the pan lightly on the counter to remove any large air bubbles.

7. Bake for 10 to 12 minutes, or until the top springs back lightly when touched and a toothpick inserted in the center comes out clean. Do not overbake or the cake will crack.

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, invert it onto the cocoa-dusted towel, and carefully peel off the parchment paper.

10. Starting from a short end, roll the warm cake up in the towel into a tight spiral and place it on a wire rack to cool completely.

11. To make the coconut pecan filling, combine evaporated milk, egg yolks, brown sugar, and butter in a medium saucepan set over medium heat, whisking constantly until the mixture thickens and gently bubbles, 8 to 10 minutes.

12. Remove the pan from the heat and stir in vanilla extract, toasted shredded coconut, and chopped pecans. Let the filling cool to room temperature; it will thicken as it cools.

13. When the cake is completely cool, carefully unroll it. Spread the coconut pecan filling evenly over the surface of the cake, leaving a small 1/2 inch border around the edges.

14. Re-roll the cake without the towel, starting from the same short end, and place the roll seam side down on a serving platter or sheet of parchment.

15. For the ganache, place the chocolate chips in a heatproof bowl. Heat the heavy cream in a small saucepan until just steaming, then pour it over the chocolate and let sit for 2 minutes.

16. Add the light corn syrup if using, then whisk the mixture until smooth, glossy, and completely melted. Let the ganache sit for 5 to 10 minutes to thicken slightly.

17. Spoon or pour the ganache over the top of the cake roll, letting it drip slightly down the sides for a drip-cake look.

18. Immediately sprinkle the top with toasted shredded coconut and pecan halves, pressing very gently so they adhere to the soft ganache.

19. Refrigerate the cake for at least 2 hours, or until the filling is firm and the ganache is set enough to slice cleanly.

20. To serve, use a long serrated knife to cut the cake into 10 to 12 slices, wiping the blade clean between cuts for the neatest spirals.