Preheat the oven to 350°F. Line a 15x10x1 jelly roll pan with parchment paper and spray with nonstick spray. Set it aside.
In a small mixing bowl, whisk together the flour, cocoa powder, baking powder and salt. Set it aside.
Using either a stand mixer, or a medium-size mixing bowl and a handheld mixer on high, beat together the eggs, sugar, vegetable oil and vanilla for 4 to 5 minutes until the mixture is a frothy pale yellow.
Fold in the flour mixture.
Evenly pour the cake batter into the prepared pan. Use a silicone spatula or an offset spatula to spread the cake batter. Bake for 10 to 12 minutes.
Remove the cake from the oven, and using a sharp knife, carefully run the tip along the edges of the pan that were not covered by the parchment paper.
Heavily dust the top of the tea towel with the powdered sugar.
Immediately place the dusted tea towel powdered side down on top of the cake.
Lay the cutting board on top of the tea towel. The cake pan will be hot, so you will need to be careful to protect your hands. Quickly flip the cake pan over so that the cake is lying on top of the dusted towel.
Carefully and slowly peel the parchment away from the cake.
Heavily dust the top of the cake with the remaining powdered sugar.
Flip one end of the tea towel over one of the short ends of the cake. Carefully begin to roll one end towards the other. Once rolled, set aside to completely cool.