Preheat the oven to 350F (180C). Grease a 12×16 inch (30x40cm) baking sheet and line with parchment paper.
In a medium bowl, sieve and whisk flour with cocoa powder, baking powder and salt. Set aside.
In a large bowl, add eggs, vanilla and sugar.
Beat with an electric mixer until lemon yellow and foamy.
Add oil and mix until well incorporated.
Incorporate the flour in batches.
Using a spatula, gently fold in the flour mixture.
Pour the batter into the prepared pan.
Bake for about 8-10 minutes until a toothpick inserted into the center comes out clean.
Sprinkle with powdered sugar. This helps the cake not stick.
Flip the cake over a kitchen towel.
Remove the parchment paper.
Roll with the kitchen towel inside. You will have to do it while it is still hot/warm otherwise it cracks. Let cool completely.