Step 1: Prepare the Chocolate Sponge Cake

1. Preheat your oven to 350°F (175°C). Grease a 10×15-inch jelly roll pan and line it with parchment paper.
2. In a large mixing bowl, beat the eggs and sugar with a hand mixer on high speed until thick and pale, about 5 minutes.
3. Sift together the flour, cocoa powder, and salt. Gently fold the dry ingredients into the egg mixture until combined.
4. Pour the batter into the prepared pan, spreading it evenly. Bake for 10-12 minutes, or until the cake springs back when lightly touched.
5. While the cake is warm, turn it out onto a clean kitchen towel dusted with cocoa powder. Carefully peel off the parchment paper and roll the cake up in the towel. Let it cool completely.

Step 2: Make the Coconut Pecan Filling

6. In a saucepan over medium heat, whisk together evaporated milk, sugar, egg yolk, and butter. Cook until thickened, about 5 minutes, stirring constantly.
7. Remove from heat and stir in coconut, pecans, and vanilla extract. Let the filling cool to room temperature.

Step 3: Assemble the Roll Cake

8. Unroll the cooled cake and spread the coconut pecan filling evenly over the surface. Gently roll the cake back up, seam-side down.

Step 4: Prepare the Ganache Topping

9. In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer. Remove from heat and pour over the chocolate chips. Let it sit for 2 minutes, then whisk until smooth. Stir in vanilla extract.
10. Pour the ganache over the rolled cake, letting it drip down the sides.

Step 5: Chill and Serve

11. Refrigerate the cake for at least 30 minutes to set the ganache. Slice and serve chilled or at room temperature.