Step 1: Prepare the Cake Batter

1. Preheat the oven to 350°F. Line a 15x10-inch jelly roll pan with parchment paper and spray with non-stick baking spray.
2. In a small bowl, whisk together flour, baking powder, and salt.
3. In a large bowl, beat eggs on high speed for 3 minutes until pale and foamy. Gradually add sugar, mixing until thick.
4. Add vegetable oil, buttermilk, apple cider vinegar, and vanilla extract, mixing until combined.
5. Fold in the dry ingredients gently to avoid deflating the batter.

Step 2: Create the Galaxy Swirl

6. Divide the batter evenly into four bowls. Add black, purple, teal, and blue food gel to each bowl and stir until fully colored.
7. Drizzle the colors into the prepared pan, alternating to create a marbled effect.
8. Lightly swirl with a toothpick or skewer for a galaxy look.

Step 3: Bake & Roll the Cake

9. Bake for 12-13 minutes, until the cake springs back when touched.
10. While baking, prepare a clean kitchen towel dusted with powdered sugar.
11. Once baked, immediately flip the cake onto the towel and carefully peel off the parchment paper.
12. Roll the cake with the towel inside and place on a cooling rack to cool completely.

Step 4: Prepare the Filling

13. In a bowl, beat cream cheese and powdered sugar until fluffy.
14. Fold in Cool Whip gently until smooth.

Step 5: Fill & Re-Roll the Cake

15. Unroll the cooled cake and spread the filling evenly, leaving a ½-inch border around the edges.
16. Roll the cake back up tightly (without the towel) and place seam-side down on a tray.
17. Refrigerate for at least 30 minutes to set.

Step 6: Make the Chocolate Ganache

18. Place chocolate chips in a heatproof bowl.
19. Heat heavy cream in a saucepan until just before boiling, then pour over the chocolate.
20. Let sit for 1-2 minutes, then stir until smooth.
21. Mix in black food coloring to deepen the color.

Step 7: Decorate the Cake

22. Place the chilled cake roll on a wire rack over a tray.
23. Pour the ganache over the cake, using a spatula to smooth.
24. Sprinkle with edible glitter, star sprinkles, and metallic sugar pearls.
25. Return to the refrigerator for 20 minutes to set before slicing.