Preheat the oven to 350°F.
Line a 15x10-inch jelly roll pan with parchment paper. Leave extra parchment paper hanging over the 15-inch sides for easy removal of the cake. You can also spray the parchment paper with a non-stick spray, but it is not necessary.
In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt until combined. Set aside.
In a separate bowl, whisk together eggs and granulated sugar for about 1 minute, or until thick. Add in the oil, vanilla extract, and coffee (use hot water if you don't have coffee) until combined.
Fold in the flour mixture and stir until combined.
Pour the batter into your prepared jelly roll pan. Smooth out the batter and gently tap on the counter.
Bake in a 350°F oven for 10-12 minutes, or until the center no longer appears wet and an inserted toothpick is removed with a few crumbs.
One a clean hard surface such as a countertop, lay out a clean dish towel and generously sprinkle with confectioners sugar or cocoa powder.
Once the cake is done baking, carefully (using oven mitts) flip it over onto the clean dish towel in one quick motion. Fold about 2 inches of the towel over the edge and start rolling the cake up from the short end into a tight roll. Allow to cool for 2-3 hours, or until completely room temperature.